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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Charge Pump DesignAdditional Slides
Vishal SaxenaECE, Boise State University
Nov 02, 2010
Vishal Saxena | Charge Pump Design 1/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Introduction
Charge pumps are widely used to generate voltages beyondnormal supply range
high voltages for programming and erasing of floating gatein EEPROMs and Flash memoriesnegative voltages for substrate bias for reducing leakage incertain digital designs
Typically generate 16-18V from 1.8V supply for programand erase in a Flash memory
have multiple program voltages in multi-level cell (MLC)Flash memory
A Closed loop-system with pump output voltage regulationis typically employed
Vishal Saxena | Charge Pump Design 2/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Introduction
Charge pumps are widely used to generate voltages beyondnormal supply range
high voltages for programming and erasing of floating gatein EEPROMs and Flash memoriesnegative voltages for substrate bias for reducing leakage incertain digital designs
Typically generate 16-18V from 1.8V supply for programand erase in a Flash memory
have multiple program voltages in multi-level cell (MLC)Flash memory
A Closed loop-system with pump output voltage regulationis typically employed
Vishal Saxena | Charge Pump Design 2/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Introduction
Charge pumps are widely used to generate voltages beyondnormal supply range
high voltages for programming and erasing of floating gatein EEPROMs and Flash memoriesnegative voltages for substrate bias for reducing leakage incertain digital designs
Typically generate 16-18V from 1.8V supply for programand erase in a Flash memory
have multiple program voltages in multi-level cell (MLC)Flash memory
A Closed loop-system with pump output voltage regulationis typically employed
Vishal Saxena | Charge Pump Design 2/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Introduction
Charge pumps are widely used to generate voltages beyondnormal supply range
high voltages for programming and erasing of floating gatein EEPROMs and Flash memoriesnegative voltages for substrate bias for reducing leakage incertain digital designs
Typically generate 16-18V from 1.8V supply for programand erase in a Flash memory
have multiple program voltages in multi-level cell (MLC)Flash memory
A Closed loop-system with pump output voltage regulationis typically employed
Vishal Saxena | Charge Pump Design 2/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Introduction
Charge pumps are widely used to generate voltages beyondnormal supply range
high voltages for programming and erasing of floating gatein EEPROMs and Flash memoriesnegative voltages for substrate bias for reducing leakage incertain digital designs
Typically generate 16-18V from 1.8V supply for programand erase in a Flash memory
have multiple program voltages in multi-level cell (MLC)Flash memory
A Closed loop-system with pump output voltage regulationis typically employed
Vishal Saxena | Charge Pump Design 2/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Introduction
Charge pumps are widely used to generate voltages beyondnormal supply range
high voltages for programming and erasing of floating gatein EEPROMs and Flash memoriesnegative voltages for substrate bias for reducing leakage incertain digital designs
Typically generate 16-18V from 1.8V supply for programand erase in a Flash memory
have multiple program voltages in multi-level cell (MLC)Flash memory
A Closed loop-system with pump output voltage regulationis typically employed
Vishal Saxena | Charge Pump Design 2/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Dickson Charge Pump
Cascade more number of stagesTwo-phase clock used for charge transfer during both thephases
VDD
φ1
φ2
φ1
φ2
C1 C1 C1 C1
CL
Vishal Saxena | Charge Pump Design 3/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Dickson Charge Pump
Cascade more number of stagesTwo-phase clock used for charge transfer during both thephases
VDD
φ1
φ2
φ1
φ2
C1 C1 C1 C1
CL
Vishal Saxena | Charge Pump Design 3/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Dickson Charge Pump Operation
Assume, small capacitive load and negligible parasitics. Neglect bodyeffect.
Vout = N(VDD − VTHN)
VDD
φ1
φ2
φ1
φ2
C1 C1 C1 C1
CL
VDD-VTHN
Vishal Saxena | Charge Pump Design 4/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Dickson Charge Pump Operation
Assume, small capacitive load and negligible parasitics. Neglect bodyeffect.
Vout = N(VDD − VTHN)
VDD
φ1
φ2
φ1
φ2
C1 C1 C1 C1
CL
2VDD-VTHN 2VDD-2VTHN
Vishal Saxena | Charge Pump Design 4/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Dickson Charge Pump Operation
Assume, small capacitive load and negligible parasitics. Neglect bodyeffect.
Vout = N(VDD − VTHN)
VDD
φ1
φ2
φ1
φ2
C1 C1 C1 C1
CL
VDD-VTHN 2VDD-2VTHN
Vishal Saxena | Charge Pump Design 4/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Dickson Charge Pump Operation
Assume, small capacitive load and negligible parasitics. Neglect bodyeffect.
Vout = N(VDD − VTHN)
VDD
φ1
φ2
φ1
φ2
C1 C1 C1 C1
CL
VDD-VTHN 3VDD-2VTHN 3VDD-3VTHN 3VDD-4VTHN
Vishal Saxena | Charge Pump Design 4/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Dickson Charge Pump Operation
Assume, small capacitive load and negligible parasitics. Neglect bodyeffect.
Vout = N(VDD − VTHN)
VDD
φ1
φ2
φ1
φ2
C1 C1 C1 C1
CL
2VDD-VTHN 2VDD-2VTHN 4VDD-3VTHN (N+1)VDD-NVTHN N(VDD-VTHN)
Vishal Saxena | Charge Pump Design 4/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Dickson Charge Pump Operation
Assume, small capacitive load and negligible parasitics. Neglect bodyeffect.
Vout = N(VDD − VTHN)
VDD
φ1
φ2
φ1
φ2
C1 C1 C1 C1
CL
2VDD-VTHN 2VDD-2VTHN 4VDD-3VTHN (N+1)VDD-NVTHN N(VDD-VTHN)
Vishal Saxena | Charge Pump Design 4/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump
Bootstrap the gates of the charge transfer devices (M1, M3,. . .) toavoid the VTHN drop
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
Cb1
φ2
φ3
C1
φ1
C1
CL
Vout
φ1
φ3
φ2
φ4
Vishal Saxena | Charge Pump Design 5/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump contd.
Precharge the gate of the chargetransfer device M1 (i.e. node na) inone half-cycle and discharge in theother half
Cb1 is the boosting capacitor
boost the node na by VDD inthe charge transfer phase (φ2 ishigh)full charge is passed from n1 ton2
VTHN drop is cancelled!
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
Vishal Saxena | Charge Pump Design 6/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump contd.
Precharge the gate of the chargetransfer device M1 (i.e. node na) inone half-cycle and discharge in theother half
Cb1 is the boosting capacitor
boost the node na by VDD inthe charge transfer phase (φ2 ishigh)full charge is passed from n1 ton2
VTHN drop is cancelled!
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
Vishal Saxena | Charge Pump Design 6/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump contd.
Precharge the gate of the chargetransfer device M1 (i.e. node na) inone half-cycle and discharge in theother half
Cb1 is the boosting capacitor
boost the node na by VDD inthe charge transfer phase (φ2 ishigh)full charge is passed from n1 ton2
VTHN drop is cancelled!
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
Vishal Saxena | Charge Pump Design 6/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump contd.
Precharge the gate of the chargetransfer device M1 (i.e. node na) inone half-cycle and discharge in theother half
Cb1 is the boosting capacitor
boost the node na by VDD inthe charge transfer phase (φ2 ishigh)full charge is passed from n1 ton2
VTHN drop is cancelled!
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
Vishal Saxena | Charge Pump Design 6/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump contd.
Precharge the gate of the chargetransfer device M1 (i.e. node na) inone half-cycle and discharge in theother half
Cb1 is the boosting capacitor
boost the node na by VDD inthe charge transfer phase (φ2 ishigh)full charge is passed from n1 ton2
VTHN drop is cancelled!
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
Vishal Saxena | Charge Pump Design 6/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump
Overlap between φ1 and φ3 byroughly 10% of TCK
precharge gate of the transferdevice to its drain potentialbefore bootstrapping occursprevent backward leakage ofcharge
φ2 and φ4 are used to boost thepotential of nodes na and nb resp.
φ2 shouldn’t overlap with φ3 inhigh phaseφ4 shouldn’t overlap with φ1 inhigh phase
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
Vishal Saxena | Charge Pump Design 7/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump
Overlap between φ1 and φ3 byroughly 10% of TCK
precharge gate of the transferdevice to its drain potentialbefore bootstrapping occursprevent backward leakage ofcharge
φ2 and φ4 are used to boost thepotential of nodes na and nb resp.
φ2 shouldn’t overlap with φ3 inhigh phaseφ4 shouldn’t overlap with φ1 inhigh phase
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
Vishal Saxena | Charge Pump Design 7/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump
Overlap between φ1 and φ3 byroughly 10% of TCK
precharge gate of the transferdevice to its drain potentialbefore bootstrapping occursprevent backward leakage ofcharge
φ2 and φ4 are used to boost thepotential of nodes na and nb resp.
φ2 shouldn’t overlap with φ3 inhigh phaseφ4 shouldn’t overlap with φ1 inhigh phase
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
Vishal Saxena | Charge Pump Design 7/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump
Overlap between φ1 and φ3 byroughly 10% of TCK
precharge gate of the transferdevice to its drain potentialbefore bootstrapping occursprevent backward leakage ofcharge
φ2 and φ4 are used to boost thepotential of nodes na and nb resp.
φ2 shouldn’t overlap with φ3 inhigh phaseφ4 shouldn’t overlap with φ1 inhigh phase
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
Vishal Saxena | Charge Pump Design 7/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump
Overlap between φ1 and φ3 byroughly 10% of TCK
precharge gate of the transferdevice to its drain potentialbefore bootstrapping occursprevent backward leakage ofcharge
φ2 and φ4 are used to boost thepotential of nodes na and nb resp.
φ2 shouldn’t overlap with φ3 inhigh phaseφ4 shouldn’t overlap with φ1 inhigh phase
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
Vishal Saxena | Charge Pump Design 7/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump
Overlap between φ1 and φ3 byroughly 10% of TCK
precharge gate of the transferdevice to its drain potentialbefore bootstrapping occursprevent backward leakage ofcharge
φ2 and φ4 are used to boost thepotential of nodes na and nb resp.
φ2 shouldn’t overlap with φ3 inhigh phaseφ4 shouldn’t overlap with φ1 inhigh phase
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
Vishal Saxena | Charge Pump Design 7/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump Operation
Assume steady-stateconditions
φ1 goes high−→ na isprecharged to 2VDD − VTHN
φ3 goes low−→M2 is off
φ2 goes high−→ na isbootstrapped to 3VDD − VTHN
full charge is transferredthrough M1
φ3 goes high−→ nb isprecharged to 3VDD − VTHN
φ1 goes low−→M4 is off
φ4 goes high−→ nb isbootstrapped to 4VDD − VTHN
full charge is transferredthrough M2
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
VDD-VTHN 3VDD-VTHN
VDD-VTHN 4VDD-VTHN
3VDD-VTHN
Vishal Saxena | Charge Pump Design 8/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump Operation
Assume steady-stateconditions
φ1 goes high−→ na isprecharged to 2VDD − VTHN
φ3 goes low−→M2 is off
φ2 goes high−→ na isbootstrapped to 3VDD − VTHN
full charge is transferredthrough M1
φ3 goes high−→ nb isprecharged to 3VDD − VTHN
φ1 goes low−→M4 is off
φ4 goes high−→ nb isbootstrapped to 4VDD − VTHN
full charge is transferredthrough M2
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
2VDD-VTHN 3VDD-VTHN
2VDD-VTHN 3VDD-VTHN
4VDD-VTHN
Vishal Saxena | Charge Pump Design 8/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump Operation
Assume steady-stateconditions
φ1 goes high−→ na isprecharged to 2VDD − VTHN
φ3 goes low−→M2 is off
φ2 goes high−→ na isbootstrapped to 3VDD − VTHN
full charge is transferredthrough M1
φ3 goes high−→ nb isprecharged to 3VDD − VTHN
φ1 goes low−→M4 is off
φ4 goes high−→ nb isbootstrapped to 4VDD − VTHN
full charge is transferredthrough M2
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
2VDD-VTHN 2VDD-VTHN-∆V
2VDD-VTHN 2VDD-VTHN-∆V
4VDD-VTHN
Vishal Saxena | Charge Pump Design 8/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump Operation
Assume steady-stateconditions
φ1 goes high−→ na isprecharged to 2VDD − VTHN
φ3 goes low−→M2 is off
φ2 goes high−→ na isbootstrapped to 3VDD − VTHN
full charge is transferredthrough M1
φ3 goes high−→ nb isprecharged to 3VDD − VTHN
φ1 goes low−→M4 is off
φ4 goes high−→ nb isbootstrapped to 4VDD − VTHN
full charge is transferredthrough M2
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
2VDD-VTHN 2VDD-VTHN
3VDD-VTHN VDD-VTHN
4VDD-VTHN
Q
Vishal Saxena | Charge Pump Design 8/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump Operation
Assume steady-stateconditions
φ1 goes high−→ na isprecharged to 2VDD − VTHN
φ3 goes low−→M2 is off
φ2 goes high−→ na isbootstrapped to 3VDD − VTHN
full charge is transferredthrough M1
φ3 goes high−→ nb isprecharged to 3VDD − VTHN
φ1 goes low−→M4 is off
φ4 goes high−→ nb isbootstrapped to 4VDD − VTHN
full charge is transferredthrough M2
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
2VDD-VTHN 3VDD-VTHN
2VDD-VTHN 3VDD-VTHN
4VDD-VTHN
Vishal Saxena | Charge Pump Design 8/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump Operation
Assume steady-stateconditions
φ1 goes high−→ na isprecharged to 2VDD − VTHN
φ3 goes low−→M2 is off
φ2 goes high−→ na isbootstrapped to 3VDD − VTHN
full charge is transferredthrough M1
φ3 goes high−→ nb isprecharged to 3VDD − VTHN
φ1 goes low−→M4 is off
φ4 goes high−→ nb isbootstrapped to 4VDD − VTHN
full charge is transferredthrough M2
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
VDD-VTHN 3VDD-VTHN
VDD-VTHN 3VDD-VTHN
3VDD-VTHN-∆V
Vishal Saxena | Charge Pump Design 8/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Four-phase Charge Pump Operation
Assume steady-stateconditions
φ1 goes high−→ na isprecharged to 2VDD − VTHN
φ3 goes low−→M2 is off
φ2 goes high−→ na isbootstrapped to 3VDD − VTHN
full charge is transferredthrough M1
φ3 goes high−→ nb isprecharged to 3VDD − VTHN
φ1 goes low−→M4 is off
φ4 goes high−→ nb isbootstrapped to 4VDD − VTHN
full charge is transferredthrough M2
VDD
φ1
C1
M0
Cb1
φ2
n1
na
M1
M2
Cb1
φ4
n2
nb
M3
M4
φ3
C1
φ1
C1
φ1
φ3
φ2
φ4
VDD-VTHN 3VDD-VTHN
VDD-VTHN 4VDD-VTHN
3VDD-VTHN
Q
Vishal Saxena | Charge Pump Design 8/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Other Architectures: Controllable BodyVoltage
Adjust bulk voltage to get rid of the body effect [3].
Better than Dickson CP, butVTHN0 drop still exists.
Vishal Saxena | Charge Pump Design 9/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Other Architectures: Controllable BodyVoltage
Adjust bulk voltage to get rid of the body effect [3].
Better than Dickson CP, butVTHN0 drop still exists.
Vishal Saxena | Charge Pump Design 9/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Non-Overlapping Clocks
?φ1
φ2
CK
φ1
φ2
CK
Vishal Saxena | Charge Pump Design 10/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Non-Overlapping Clocks
?φ1
φ2
CK
φ1
φ2
CK
A
B
C
D
A
Vishal Saxena | Charge Pump Design 10/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Non-Overlapping Clocks: State Machine
State Diagram
0 1 0 0
0 0 1 0
0
1
10
0
1
φ1 φ2
CK Truth TableCK φ1 φ2 φ
′1 φ
′2
0 0 1 0 11 0 1 0 01 0 0 1 01 1 0 1 00 1 0 0 00 0 0 0 1
Vishal Saxena | Charge Pump Design 11/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Non-Overlapping Clocks: Karnaugh Maps
CK/φ1 φ2 00 01 11 100 0 0 X 01 1 0 X 1
φ′1 = CK · φ2 = CK · φ2
CK/φ1 φ2 00 01 11 100 1 1 X 01 0 0 X 0
φ′2 = CK · φ1 = CK · φ1
Vishal Saxena | Charge Pump Design 12/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Non-Overlapping Clocks: Generation Circuit 1
Implements logic φ′1 = CK · φ2 and φ
′2 = CK · φ1
Non-overlap time is set by the NAND’s tpLH
φ1
φ2
CK φ1
φ2
Vishal Saxena | Charge Pump Design 13/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Non-Overlapping Clocks: Generation Circuit 1
Implements logic φ′1 = CK · φ2 and φ
′2 = CK · φ1
Non-overlap time is set by the NAND’s tpLH
φ1
φ2
CK φ1
φ2
Vishal Saxena | Charge Pump Design 13/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Non-Overlapping Clocks: Generation Circuit 2
Can increase non-overlap time be inserting extra delay
φ1
φ2
CK φ1
φ2
delay
Vishal Saxena | Charge Pump Design 14/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Non-Overlapping Clocks: Generation Circuit 3
Insert a matched delay to the inverter for perfect timing.
φ1
φ2
CK φ1
φ2
delayVDD
Vishal Saxena | Charge Pump Design 15/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Non-Overlapping Clocks: Generation Circuit 4
Another topology with larger non-overlap time.
φ1
φ2
CK φ1
φ2
delay
Vishal Saxena | Charge Pump Design 16/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
4 Non-Overlapping Clocks Phases
The following circuit generates four non-overlapping clockphases.
The phase alignment for 4-phase charge pump is slighlydifferent. Think about it!
Vishal Saxena | Charge Pump Design 17/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
4 Non-Overlapping Clocks Phases
The following circuit generates four non-overlapping clockphases.
The phase alignment for 4-phase charge pump is slighlydifferent. Think about it!
Vishal Saxena | Charge Pump Design 17/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Regulated Charge Pump
Feedback to regulate the charge pump output to a desired voltage
A sensing circuit compares the pump output to a reference andenables the clock
A simple method is to switch the ring oscillator on and off
large ripples in the output
Oscillator with Enable
Charge Pump
Regulator with Hysteresis
φ1Enable Vpump
Ena
ble
VpS
ense
Ena
ble
Vp
φ2
VDD VDD
VDD
φ1
φ2
CL IL
Vishal Saxena | Charge Pump Design 18/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Regulated Charge Pump
Feedback to regulate the charge pump output to a desired voltage
A sensing circuit compares the pump output to a reference andenables the clock
A simple method is to switch the ring oscillator on and off
large ripples in the output
Oscillator with Enable
Charge Pump
Regulator with Hysteresis
φ1Enable Vpump
Ena
ble
VpS
ense
Ena
ble
Vp
φ2
VDD VDD
VDD
φ1
φ2
CL IL
Vishal Saxena | Charge Pump Design 18/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Regulated Charge Pump
Feedback to regulate the charge pump output to a desired voltage
A sensing circuit compares the pump output to a reference andenables the clock
A simple method is to switch the ring oscillator on and off
large ripples in the output
Oscillator with Enable
Charge Pump
Regulator with Hysteresis
φ1Enable Vpump
Ena
ble
VpS
ense
Ena
ble
Vp
φ2
VDD VDD
VDD
φ1
φ2
CL IL
Vishal Saxena | Charge Pump Design 18/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Regulated Charge Pump
Feedback to regulate the charge pump output to a desired voltage
A sensing circuit compares the pump output to a reference andenables the clock
A simple method is to switch the ring oscillator on and off
large ripples in the output
Oscillator with Enable
Charge Pump
Regulator with Hysteresis
φ1Enable Vpump
Ena
ble
VpS
ense
Ena
ble
Vp
φ2
VDD VDD
VDD
φ1
φ2
CL IL
Vishal Saxena | Charge Pump Design 18/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Pump Regulation: Capacitor Divider
Cap values C1 and C2 change with parasitics.Capacitive loading on the pump (may be insignificant w.r.t.CL)Faster feedback control.
Vishal Saxena | Charge Pump Design 19/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Pump Regulation: Capacitor Divider
Cap values C1 and C2 change with parasitics.Capacitive loading on the pump (may be insignificant w.r.t.CL)Faster feedback control.
Vishal Saxena | Charge Pump Design 19/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Pump Regulation: Capacitor Divider
Cap values C1 and C2 change with parasitics.Capacitive loading on the pump (may be insignificant w.r.t.CL)Faster feedback control.
Vishal Saxena | Charge Pump Design 19/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Pump Regulation: Resistor Divider
Resistors may load the pump output.
Use large resistors → Large layout area
RC delay
Vishal Saxena | Charge Pump Design 20/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Pump Regulation: Resistor Divider
Resistors may load the pump output.
Use large resistors → Large layout area
RC delay
Vishal Saxena | Charge Pump Design 20/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Pump Regulation: Resistor Divider
Resistors may load the pump output.
Use large resistors → Large layout area
RC delay
Vishal Saxena | Charge Pump Design 20/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Pump Regulation: Resistor Divider
Resistors may load the pump output.
Use large resistors → Large layout area
Vishal Saxena | Charge Pump Design 21/25
institution-logo
Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Pump Regulation: Resistor Divider
Resistors may load the pump output.
Use large resistors → Large layout area
Vishal Saxena | Charge Pump Design 21/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Oscillator with Enable
Use a NAND gate in the ring, while ensuring there are oddnumber of inverting stages
EnableCLK
Vishal Saxena | Charge Pump Design 22/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
VCO based Regulation
Use a voltage-controlled oscillator (VCO) for smootherregulation of the output[5].
cleaner VCO switching leads to much lower pump outputripples.
Vishal Saxena | Charge Pump Design 23/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
VCO based Regulation
Use a voltage-controlled oscillator (VCO) for smootherregulation of the output[5].
cleaner VCO switching leads to much lower pump outputripples.
Vishal Saxena | Charge Pump Design 23/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
Regulation with Dynamic Buffer
Automatically tune the buffer strength to regulate theoutput[5].
Vishal Saxena | Charge Pump Design 24/25
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Basic Concept Dickson Charge Pump 4-phase Charge Pump Non-overlapping Clocks Voltage Regulation
References I
Baker, R. J., CMOS Circuit Design, Layout and Simulation, revised 2nd Edition,Wiley-IEEE, 2008.
Pan, F., Samaddar, T., Charge Pump Circuit Design, McGraw-Hill, 2006.
Shin, J., Chung, I., Park, Y., Min, H., “A new charge pump without degradation onthreshold voltage due to body effect,” IEEE SBCCI, Aug 2003.
Soldera, J., Boas, A., Olmos, A., “A low-ripple fully integrated charge pump regulator”IEEE JSSC, vol. 41, no. 2, Feb 2006.
Lee, J-Y et al, “A regulated charpe pump with small ripple voltage and fast start-up,”IEEE JSSC, vol. 41, no. 2, Feb 2006.
Palumbo, G., Pappalardo, D., “Charge Pump Circuits: An overview on design strategiesand topologies ,” IEEE Circuits and Systems Magazine, Q1 2010
Vishal Saxena | Charge Pump Design 25/25
