AD ADP5071 Independent positive and negative output Datasheet

2 A/1.2 A DC-to-DC Switching Regulator with
Independent Positive and Negative Outputs
ADP5071
Data Sheet
FEATURES
TYPICAL APPLICATION CIRCUIT
ADP5071
SS
INBK
RC1
L1
COMP1
VPOS
CC1
SW1
EN1
D1
RFT1
CVREG
FB1
VREG
RFB1
VIN
CIN1
PVIN1
PVIN2
PVINSYS
PGND
EN2
VREF
COUT1
CVREF
RFB2
RC2
FB2
COMP2
CC2
SYNC/FREQ
SLEW
SEQ
AGND
COUT2
RFT2
SW2
D2
L2
VNEG
12069-001
Wide input supply voltage range: 2.85 V to 15 V
Generates well regulated, independently resistor
programmable VPOS and VNEG outputs
Boost regulator to generate VPOS output
Adjustable positive output to 39 V
Integrated 2.0 A main switch
Optional single-ended primary-inductor converter
(SEPIC) configuration for automatic step-up/step-down
Inverting regulator to generate VNEG output
Adjustable negative output to VIN − 39 V
Integrated 1.2 A main switch
True shutdown for both positive and negative outputs
1.2 MHz/2.4 MHz switching frequency with optional external
frequency synchronization from 1.0 MHz to 2.6 MHz
Resistor programmable soft start timer
Slew rate control for lower system noise
Individual precision enable and flexible start-up sequence
control for symmetric start, VPOS first, or VNEG first
Out-of-phase operation
UVLO, OCP, OVP, and TSD protection
4 mm × 4 mm, 20-lead LFCSP and 20-lead TSSOP
−40°C to +125°C junction temperature range
Supported by the ADIsimPower tool set
Figure 1.
APPLICATIONS
Bipolar amplifiers, ADCs, DACs, and multiplexers
Charge-coupled device (CCD) bias supply
Optical module supply
RF power amplifier (PA) bias
GENERAL DESCRIPTION
The ADP5071 is a dual high performance dc-to-dc regulator that
generates independently regulated positive and negative rails.
The input voltage range of 2.85 V to 15 V supports a wide variety of
applications. The integrated main switch in both regulators enables
generation of an adjustable positive output voltage up to +39 V
and a negative output voltage down to −39 V below input voltage.
The ADP5071 operates at a pin selected 1.2 MHz/2.4 MHz
switching frequency. The ADP5071 can synchronize with an
external oscillator from 1.0 MHz to 2.6 MHz to ease noise
filtering in sensitive applications. Both regulators implement
programmable slew rate control circuitry for the MOSFET
driver stage to reduce electromagnetic interference (EMI).
Flexible start-up sequencing is provided with the options of
manual enable, simultaneous mode, positive supply first, and
negative supply first.
Rev. A
The ADP5071 includes a fixed internal or resistor programmable
soft start timer to prevent inrush current at power-up. During
shutdown, both regulators completely disconnect the loads from
the input supply to provide a true shutdown.
Other key safety features in the ADP5071 include overcurrent
protection (OCP), overvoltage protection (OVP), thermal
shutdown (TSD), and input undervoltage lockout (UVLO).
The ADP5071 is available in a 20-lead LFCSP or in a 20-lead
TSSOP and is rated for a −40°C to +125°C junction temperature
range.
Table 1. Family Models
Model
ADP5070
ADP5071
Boost Switch (A)
1.0
2.0
Inverter Switch (A)
0.6
1.2
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Last Content Update: 11/01/2016
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Application Notes
• AN-1366: Using the ADP5070/ADP5071 to Create Positive
and Negative Voltage Rails when VOUT < VIN
• AN-1368: Ferrite Bead Demystified
Data Sheet
• ADP5071: 2 A/1.2 A DC-to-DC Switching Regulator with
Independent Positive and Negative Outputs Data Sheet
User Guides
• UG-758: Evaluating the ADP5070CP/ADP5071CP LFCSP
DC-to-DC Switching Regulators/Converters
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ADP5071
Data Sheet
TABLE OF CONTENTS
Features .............................................................................................. 1
Soft Start ...................................................................................... 15
Applications ....................................................................................... 1
Slew Rate Control ....................................................................... 15
Typical Application Circuit ............................................................. 1
Current-Limit Protection ............................................................ 15
General Description ......................................................................... 1
Overvoltage Protection .............................................................. 15
Revision History ............................................................................... 2
Thermal Shutdown .................................................................... 15
Specifications..................................................................................... 3
Start-Up Sequence ...................................................................... 15
Absolute Maximum Ratings ............................................................ 5
Applications Information .............................................................. 17
Thermal Resistance ...................................................................... 5
ADIsimPower Design Tool ....................................................... 17
ESD Caution .................................................................................. 5
Component Selection ................................................................ 17
Pin Configurations and Function Descriptions ........................... 6
Loop Compensation .................................................................. 20
Typical Performance Characteristics ............................................. 8
Common Applications .............................................................. 22
Theory of Operation ...................................................................... 14
Super Low Noise With Optional LDOs................................... 24
PWM Mode ................................................................................. 14
SEPIC Step-Up/Step-Down Operation ................................... 25
PSM Mode ................................................................................... 14
Layout Considerations ............................................................... 26
Undervoltage Lockout (UVLO) ............................................... 14
Outline Dimensions ....................................................................... 27
Oscillator and Synchronization ................................................ 14
Ordering Guide .......................................................................... 27
Internal Regulators ..................................................................... 14
Precision Enabling ...................................................................... 15
REVISION HISTORY
6/15—Rev. 0 to Rev. A
Added 20-Lead TSSOP ...................................................... Universal
Change to Pull-Down Resistance Parameter, Table 2 .................. 3
Changes to Table 3 and Table 4 ....................................................... 5
Added Figure 3, Renumbered Sequentially .................................. 6
Changes to Figure 37 Caption to Figure 39 Caption ................. 13
Changes to Internal Regulators Section ...................................... 14
Change to Soft Start Section.......................................................... 15
Changes to Component Selection Section .................................. 17
Changes to Output Capacitors Section, Soft Start Resistor Section,
and Diodes Section ......................................................................... 18
Changes to Figure 52 Caption....................................................... 26
Added Figure 53.............................................................................. 26
Updated Outline Dimensions ....................................................... 27
Changes to Ordering Guide .......................................................... 27
2/15—Revision 0: Initial Version
Rev. A | Page 2 of 27
Data Sheet
ADP5071
SPECIFICATIONS
PVIN1 = PVIN2 = PVINSYS = 2.85 V to 15 V, VPOS = 15 V, VNEG = −15 V, fSW = 1200 kHz, TJ = −40°C to +125°C for minimum/maximum
specifications, and TA = 25°C for typical specifications, unless otherwise noted.
Table 2.
Parameter
INPUT SUPPLY VOLTAGE RANGE
QUIESCENT CURRENT
Operating Quiescent Current
PVIN1, PVIN2, PVINSYS (Total)
Shutdown Current
UVLO
System UVLO Threshold
Rising
Falling
Hysteresis
OSCILLATOR CIRCUIT
Switching Frequency
SYNC/FREQ Input
Input Clock Range
Input Clock Minimum On Pulse Width
Input Clock Minimum Off Pulse Width
Input Clock High Logic
Input Clock Low Logic
PRECISION ENABLING (EN1, EN2)
High Level Threshold
Low Level Threshold
Shutdown Mode
Pull-Down Resistance
INTERNAL REGULATOR
VREG Output Voltage
BOOST REGULATOR
Feedback Voltage
Feedback Voltage Accuracy
Symbol
VIN
Min
2.85
Typ
Max
15
Unit
V
Test Conditions/Comments
PVIN1, PVIN2, PVINSYS
IQ
3.5
4.0
mA
ISHDN
5
10
µA
No switching, EN1 = EN2 = high,
PVIN1 = PVIN2 = PVINSYS = 5 V
No switching, EN1 = EN2 = low,
PVIN1 = PVIN2 = PVINSYS = 5 V
VUVLO_RISING
VUVLO_FALLING
VHYS_1
2.85
2.5
2.8
2.55
0.25
V
V
V
fSW
1.130
2.240
1.200
2.400
1.270
2.560
MHz
MHz
fSYNC
tSYNC_MIN_ON
tSYNC_MIN_OFF
VH (SYNC)
VL (SYNC)
1.000
100
100
2.600
MHz
ns
ns
V
V
VTH_H
VTH_L
VTH_S
1.125
1.025
0.4
PVINSYS
1.3
0.4
1.15
1.05
1.175
1.075
V
V
V
REN
1.48
MΩ
VREG
4.25
V
VFB1
0.8
−0.5
−1.5
Feedback Bias Current
Overvoltage Protection Threshold
Load Regulation
Line Regulation
IFB1
VOV1
∆VFB1/ILOAD1
∆VFB1/VPVIN1
Error Amplifier (EA) Transconductance
Power FET On Resistance
Power FET Maximum Drain Source Voltage
Input Disconnect Switch On Resistance
Current-Limit Threshold
Minimum On Time
Minimum Off Time
gM1
RDS (ON) BOOST
VDS (MAX) BOOST
RDS (ON) INBK
ILIM (BOOST)
+0.5
+1.5
0.1
0.86
0.0003
0.002
270
2.0
300
175
39
210
2.2
50
25
Rev. A | Page 3 of 27
330
2.4
V
%
%
µA
V
%/mA
%/V
µA/V
mΩ
V
mΩ
A
ns
ns
SYNC/FREQ = low
SYNC/FREQ = high (connect to
VREG)
Internal circuitry disabled to
achieve ISHDN
TJ = 25°C
TJ = −40°C to +125°C
At FB1 pin
ILOAD11 = 5 mA to 150 mA
VPVIN1 = 2.85 V to 14.5 V, ILOAD11 =
50 mA
ADP5071
Parameter
INVERTING REGULATOR
Reference Voltage
Reference Voltage Accuracy
Symbol
Feedback Bias Current
Overvoltage Protection Threshold
IFB2
VOV2
Load Regulation
∆(VREF − VFB2)/
ILOAD2
∆(VREF − VFB2)/
VPVIN2
gM2
RDS (ON) INVERTER
VDS (MAX) INVERTER
ILIM (INVERTER)
Hiccup Time
THERMAL SHUTDOWN
Threshold
Hysteresis
Typ
Max
1.60
0.74
0.0004
%/mA
0.003
%/V
+0.5
+1.5
0.8
−0.5
−1.5
270
1200
Unit
V
%
%
V
%
%
µA
V
−0.5
−1.5
VREF − VFB2
EA Transconductance
Power FET On Resistance
Power FET Maximum Drain Source Voltage
Current-Limit Threshold
Minimum On Time
Minimum Off Time
SOFT START
Soft Start Timer for Boost and Inverting
Regulators
Min
VREF
Feedback Voltage
Feedback Voltage Accuracy
Line Regulation
1
Data Sheet
+0.5
+1.5
0.1
300
350
39
1320
60
50
330
1440
Test Conditions/Comments
TJ = 25°C
TJ = −40°C to +125°C
TJ = 25°C
TJ = −40°C to +125°C
At FB2 pin after soft start has
completed
ILOAD21 = 5 mA to 75 mA
VPVIN2 = 2.85 V to 14.5 V, ILOAD21 =
25 mA
µA/V
mΩ
V
mA
ns
ns
tSS
4
ms
SS = open
32
8 × tSS
ms
ms
SS resistor = 50 kΩ to GND
tHICCUP
TSHDN
THYS
150
15
°C
°C
ILOADx is the current through a resistive load connected across the output capacitor (where x is 1 for the boost regulator load and 2 for the inverting regulator load).
Rev. A | Page 4 of 27
Data Sheet
ADP5071
ABSOLUTE MAXIMUM RATINGS
THERMAL RESISTANCE
Table 3.
Parameter
PVIN1, PVIN2, PVINSYS
INBK
SW1
SW2
PGND, AGND
VREG
EN1, EN2, FB1, FB2, SYNC/FREQ
COMP1, COMP2, SLEW, SS,
SEQ, VREF
Operating Junction
Temperature Range
Storage Temperature Range
Soldering Conditions
Rating
−0.3 V to +18 V
−0.3 V to PVIN1 + 0.3 V
−0.3 V to +40 V
PVIN2 − 40 V to PVIN2 + 0.3 V
−0.3 V to +0.3 V
−0.3 V to lower of PVINSYS +
0.3 V or +6 V
−0.3 V to +6 V
−0.3 V to VREG + 0.3 V
θJA and ΨJT are based on a 4-layer printed circuit board (PCB)
(two signal and two power planes) with nine thermal vias
connecting the exposed pad to the ground plane as recommended
in the Layout Considerations section. θJC is measured at the top
of the package and is independent of the PCB. The ΨJT value is
more appropriate for calculating junction to case temperature in
the application.
Table 4. Thermal Resistance
−40°C to +125°C
Package Type
20-Lead LFCSP
20-Lead TSSOP
−65°C to +150°C
JEDEC J-STD-020
ESD CAUTION
Stresses at or above those listed under Absolute Maximum
Ratings may cause permanent damage to the product. This is a
stress rating only; functional operation of the product at these
or any other conditions above those indicated in the operational
section of this specification is not implied. Operation beyond
the maximum operating conditions for extended periods may
affect product reliability.
Rev. A | Page 5 of 27
θJA
60.2
58.5
θJC
36.5
35.0
ΨJT
0.63
0.60
Unit
°C/W
°C/W
ADP5071
Data Sheet
ADP5071
TOP VIEW
(Not to Scale)
15
14
13
12
11
PVIN1
VREG
AGND
VREF
FB2
NOTES
1. EXPOSED PAD. CONNECT THE EXPOSED PAD TO AGND.
1
20 SW2
SW1
2
19 PVIN2
18 PVINSYS
INBK
3
SYNC/FREQ
4
SEQ
5
SLEW
6
15 AGND
FB1
7
14 VREF
COMP1
8
13 FB2
EN1
9
12 COMP2
SS 10
12069-002
1
2
3
4
5
COMP1 6
EN1 7
SS 8
EN2 9
COMP2 10
INBK
SYNC/FREQ
SEQ
SLEW
FB1
PGND
17 PVIN1
ADP5071
TOP VIEW
16 VREG
11 EN2
12069-050
20
19
18
17
16
SW1
PGND
SW2
PVIN2
PVINSYS
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
NOTES
1. EXPOSED PAD. CONNECT THE EXPOSED PAD TO AGND.
Figure 2. 20-Lead LFCSP Pin Configuration
Figure 3. 20-Lead TSSOP Pin Configuration
Table 5. Pin Function Descriptions
Pin No.
LFCSP TSSOP
1
3
2
4
Mnemonic
INBK
SYNC/FREQ
3
5
SEQ
4
6
SLEW
5
7
FB1
6
8
COMP1
7
9
EN1
8
10
SS
9
11
EN2
10
12
COMP2
11
13
FB2
12
14
VREF
13
14
15
16
17
15
16
17
18
19
AGND
VREG
PVIN1
PVINSYS
PVIN2
Description
Input Disconnect Switch Output for the Boost Regulator.
Frequency Setting and Synchronization Input. To set the switching frequency to 2.4 MHz, pull the SYNC/FREQ
pin high. To set the switching frequency to 1.2 MHz, pull the SYNC/FREQ pin low. To synchronize the
switching frequency, connect the SYNC/FREQ pin to an external clock.
Start-Up Sequence Control. For manual VPOS/VNEG startup using an individual precision enabling pin, leave
the SEQ pin open. For simultaneous VPOS/VNEG startup when the EN2 pin rises, connect the SEQ pin to VREG
(the EN1 pin can be used to enable the internal references early, if required). For a sequenced startup, pull the
SEQ pin low. Either EN1 or EN2 can be used, and the corresponding supply is the first in sequence; hold
the other enable pin low.
Driver Stage Slew Rate Control. The SLEW pin sets the slew rate for the SW1 and SW2 drivers. For the
fastest slew rate (best efficiency), leave the SLEW pin open. For normal slew rate, connect the SLEW pin to
VREG. For the slowest slew rate (best noise performance), connect the SLEW pin to AGND.
Feedback Input for the Boost Regulator. Connect a resistor divider between the positive side of the boost
regulator output capacitor and AGND to program the output voltage.
Error Amplifier Compensation for the Boost Regulator. Connect the compensation network between this
pin and AGND.
Boost Regulator Precision Enable. The EN1 pin is compared to an internal precision reference to enable
the boost regulator output.
Soft Start Programming. Leave the SS pin open to obtain the fastest soft start time. To program a slower
soft start time, connect a resistor between the SS pin and AGND.
Inverting Regulator Precision Enable. The EN2 pin is compared to an internal precision reference to enable
the inverting regulator output.
Error Amplifier Compensation for the Inverting Regulator. Connect the compensation network between
this pin and AGND.
Feedback Input for the Inverting Regulator. Connect a resistor divider between the negative side of the
inverting regulator output capacitor and VREF to program the output voltage.
Inverting Regulator Reference Output. Connect a 1.0 μF ceramic filter capacitor between the VREF pin and
AGND.
Analog Ground.
Internal Regulator Output. Connect a 1.0 μF ceramic filter capacitor between the VREG pin and AGND.
Power Input for the Boost Regulator.
System Power Supply for the ADP5071.
Power Input for the Inverting Regulator.
Rev. A | Page 6 of 27
Data Sheet
Pin No.
LFCSP TSSOP
18
20
19
1
20
2
ADP5071
Mnemonic
SW2
PGND
SW1
EPAD
Description
Switching Node for the Inverting Regulator.
Power Ground for the Boost and Inverting Regulators.
Switching Node for the Boost Regulator.
Exposed Pad. Connect the exposed pad to AGND.
Rev. A | Page 7 of 27
ADP5071
Data Sheet
TYPICAL PERFORMANCE CHARACTERISTICS
Typical performance characteristics are generated using the standard bill of materials for each input/output combination listed in Table 9,
Table 10, and Table 11.
1000
1200
VIN = 3.3V, L = 3.3µH
VIN = 3.3V, L = 4.7µH
VIN = 5V, L = 3.3µH
VIN = 5V, L = 4.7µH
VIN = 12V, L = 10µH
VIN = 15V, L = 10µH
800
800
IOUT(MAX) (mA)
IOUT(MAX) (mA)
1000
600
600
VIN = 3.3V, L = 4.7µH
VIN = 5V, L = 6.8µH
VIN = 5V, L = 10µH
VIN = 12V, L = 6.8µH
VIN = 12V, L = 15µH
VIN = 15V, L = 10µH
VIN = 3.3V, L = 6.8µH
VIN = 15V, L = 22µH
400
400
0
10
20
30
40
50
VPOS (V)
Figure 4. Boost Regulator Maximum Output Current, fSW = 1.2 MHz,
TA = 25°C, Based on Target of 70% ILIM (BOOST)
–30
–20
–10
0
VNEG (V)
Figure 7. Inverting Regulator Maximum Output Current, fSW = 1.2 MHz,
TA = 25°C, Based on Target of 70% ILIM (INVERTER)
700
1000
VIN = 3.3V, L = 3.3µH
VIN = 3.3V, L = 4.7µH
VIN = 5V, L = 2.2µH
VIN = 5V, L = 4.7µH
VIN = 12V, L = 4.7µH
VIN = 15V, L = 6.8µH
600
500
IOUT(MAX) (mA)
800
IOUT(MAX) (mA)
0
–40
12069-003
0
12069-006
200
200
600
400
VIN = 3.3V, L = 2.2µH
VIN = 5V, L = 3.3µH
VIN = 5V, L = 4.7µH
VIN = 12V, L = 6.8µH
VIN = 15V, L = 10µH
VIN = 12V, L = 3.3µH
VIN = 15V, L = 4.7µH
400
300
200
200
10
20
40
30
50
VPOS (V)
Figure 5. Boost Regulator Maximum Output Current, fSW = 2.4 MHz,
TA = 25°C, Based on Target of 70% ILIM (BOOST)
80
80
EFFICIENCY (%)
100
40
–10
0
60
40
20
20
0
0.001
–20
Figure 8. Inverting Regulator Maximum Output Current, fSW = 2.4 MHz,
TA = 25°C, Based on Target of 70% ILIM (INVERTER)
100
60
–30
VNEG (V)
VIN = 3.3V, 1.2MHz
VIN = 3.3V, 2.4MHz
0.01
0.1
1
LOAD (A)
0
0.001
12069-005
EFFICIENCY (%)
0
–40
VIN = 3.3V, 1.2MHz
VIN = 3.3V, 2.4MHz
0.01
0.1
1
LOAD (A)
Figure 6. Boost Regulator Efficiency vs. Current Load, VIN = 3.3 V,
VPOS = 5 V, TA = 25°C
Figure 9. Inverting Regulator Efficiency vs. Current Load, VIN = 3.3 V,
VNEG = −5 V, TA = 25°C
Rev. A | Page 8 of 27
12069-008
0
12069-004
0
12069-007
100
ADP5071
100
80
80
40
20
20
VIN = 3.3V, 1.2MHz
VIN = 3.3V, 2.4MHz
VIN = 5V, 1.2MHz
VIN = 5V, 2.4MHz
0.01
0.1
1
LOAD (A)
0
0.001
80
EFFICIENCY (%)
80
20
0
0.001
0.01
0.1
1
LOAD (A)
Figure 11. Boost Regulator Efficiency vs. Current Load, VPOS = 15 V,
TA = 25°C
1
60
40
0
0.001
VIN = 3.3V, 1.2MHz
VIN = 3.3V, 2.4MHz
VIN = 5V, 1.2MHz
VIN = 5V, 2.4MHz
0.1
0.01
1
LOAD (A)
Figure 14. Inverting Regulator Efficiency vs. Current Load, VNEG = −15 V,
TA = 25°C
100
80
80
EFFICIENCY (%)
100
60
40
20
60
40
20
VIN = 5V, 1.2MHz
VIN = 5V, 2.4MHz
0.01
0.1
1
LOAD (A)
Figure 12. Boost Regulator Efficiency vs. Current Load, VPOS = 34 V,
TA = 25°C
0
0.001
12069-011
0
0.001
0.1
20
VIN = 3.3V, 1.2MHz
VIN = 3.3V, 2.4MHz
VIN = 5V, 1.2MHz
VIN = 5V, 2.4MHz
12069-010
EFFICIENCY (%)
100
40
0.01
Figure 13. Inverting Regulator Efficiency vs. Current Load, VNEG = −9 V,
TA = 25°C
100
60
VIN = 3.3V, 1.2MHz
VIN = 3.3V, 2.4MHz
VIN = 5V, 1.2MHz
VIN = 5V, 2.4MHz
LOAD (A)
Figure 10. Boost Regulator Efficiency vs. Current Load, VPOS = 9 V, TA = 25°C
EFFICIENCY (%)
40
VIN = 5V, 1.2MHz
VIN = 5V, 2.4MHz
0.01
0.1
LOAD (A)
1
12069-014
0
0.001
60
12069-013
60
12069-012
EFFICIENCY (%)
100
12069-009
EFFICIENCY (%)
Data Sheet
Figure 15. Inverting Regulator Efficiency vs. Current Load, VNEG = −34 V,
TA = 25°C
Rev. A | Page 9 of 27
Data Sheet
100
100
80
80
EFFICIENCY (%)
60
40
20
TA = +125°C
TA = +25°C
TA = –40°C
0.01
0.1
1
LOAD (A)
0.01
0.1
1
LOAD (A)
Figure 16. Boost Regulator Efficiency over Temperature,
VIN = 5 V, VPOS = 15 V, fSW = 1.2 MHz
Figure 19. Inverting Regulator Efficiency over Temperature,
VIN = 5 V, VNEG = −15 V, fSW = 1.2 MHz
0.5
0.3
0.1
–0.1
–0.3
VOUT ACCURACY
VFB1 ACCURACY
0
5
10
15
20
VIN (V)
0.1
–0.1
–0.3
VOUT ACCURACY
VREF ACCURACY
VFB2 ACCURACY
–0.5
12069-016
–0.5
0.3
0
5
10
15
20
VIN (V)
Figure 17. Boost Regulator Line Regulation, VPOS = 15 V,
fSW = 1.2 MHz, 15 mA Load, TA = 25°C
12069-019
VARIATION FROM NOMINAL (%)
0.5
VARIATION FROM NOMINAL (%)
TA = +125°C
TA = +25°C
TA = –40°C
0
0.001
12069-015
0
0.001
Figure 20. Inverting Regulator Line Regulation, VNEG = −15 V,
fSW = 1.2 MHz, 15 mA Load, TA = 25°C
0.5
LOAD REGULATION, CHANGE IN VFB2 (%)
0.5
0.3
0.1
–0.1
–0.3
1.2MHz
2.4MHz
–0.5
0
0.1
0.2
0.3
0.4
0.5
LOAD (A)
Figure 18. Boost Regulator Load Regulation, VIN = 5 V, VPOS = 15 V
0.3
0.1
–0.1
–0.3
1.2MHz
2.4MHz
–0.5
12069-017
LOAD REGULATION, CHANGE IN VFB1 (%)
40
12069-018
20
60
0
0.05
0.10
LOAD (A)
0.15
12069-020
EFFICIENCY (%)
ADP5071
Figure 21. Inverting Regulator Load Regulation, VIN = 5 V, VNEG = −15 V
Rev. A | Page 10 of 27
Data Sheet
ADP5071
0.5
0.1
–0.1
–0.3
–0.5
0
0.15
0.10
0.05
0.20
INVERTING REGULATOR LOAD (A)
Figure 22. Cross Regulation, Boost Regulator VFB1 Regulation over Inverting
Regulator Current Load, VIN = 5 V, VPOS = 15 V, VNEG = −15 V,
fSW = 2.4 MHz, TA = 25°C, Boost Regulator Run in Continuous Conduction
Mode with Fixed Load for Test
0.3
0.1
–0.1
–0.3
–0.5
–0.05
0.25
0.15
0.05
0.35
0.45
BOOST REGULATOR LOAD (A)
12069-024
VFB2 DEVIATION FROM AVERAGE VALUE (%)
0.3
12069-021
VFB1 DEVIATION FROM AVERAGE VALUE (%)
0.5
Figure 25. Cross Regulation, Inverting Regulator VFB2 Regulation over Boost
Regulator Current Load, VIN = 5 V, VPOS = 15 V, VNEG = −15 V,
fSW = 2.4 MHz, TA = 25°C, Inverting Regulator Run in Continuous Conduction
Mode with Fixed Load for Test
1.44
2.40
TA = +125°C
TA = +25°C
TA = –40°C
2.35
TA = +125°C
TA = +25°C
TA = –40°C
1.40
2.30
1.36
ILIMIT (A)
ILIMIT (A)
2.25
2.20
1.32
2.15
1.28
2.10
1.22
0
5
10
15
20
VIN (V)
1.20
12069-022
2.00
Figure 23. Boost Regulator Current Limit (ILIMIT) vs. Input Voltage (VIN)
over Temperature
0
4
6
8
10
12
14
16
VIN (V)
Figure 26. Inverting Regulator Current Limit (ILIMIT) vs. Input Voltage (VIN)
over Temperature
1.27
2.54
2.49
OSCILLATOR FREQUENCY (MHz)
TA = +125°C
TA = +25°C
TA = –40°C
2.44
2.39
2.34
2.29
TA = +125°C
TA = +25°C
TA = –40°C
1.25
1.23
1.21
1.19
1.17
2.24
0
2
4
6
8
VIN (V)
10
12
14
16
1.13
Figure 24. Oscillator Frequency vs. Input Voltage (VIN) over Temperature,
SYNC/FREQ Pin = High
0
2
4
6
8
VIN (V)
10
12
14
16
12069-026
1.15
12069-023
OSCILLATOR FREQUENCY (MHz)
2
12069-025
2.05
Figure 27. Oscillator Frequency vs. Input Voltage (VIN) over Temperature,
SYNC/FREQ Pin = Low
Rev. A | Page 11 of 27
ADP5071
Data Sheet
5.0
12
10
8
6
4
2
TA = +125°C
TA = +25°C
TA = –40°C
0
2
4
6
8
10
12
14
4.0
3.5
3.0
2.5
2.0
1.5
1.0
TA = +125°C
TA = +25°C
TA = –40°C
0.5
0
16
VIN (V)
0
12069-027
0
4.5
2
4
6
8
10
12
14
16
VIN (V)
12069-030
OPERATING QUIESCENT CURRENT (mA)
SHUTDOWN QUIESCENT CURRENT (µA)
14
Figure 31. Operating Quiescent Current vs. Input Voltage (VIN) over
Temperature, Both ENx Pins On
Figure 28. Shutdown Quiescent Current vs. Input Voltage (VIN) over
Temperature, Both ENx Pins Below Shutdown Threshold
T
T
VIN
VIN
VNEG
2
VPOS
2
1
1
VFB2
VFB1
3
B
W
4.00ms
T
CH1
5.00V
14.0ms
CH1 1V BW
12069-028
CH1 1.0V BW CH2 100mV
CH3 5.0mV BW
CH2 100mV
B
CH3 5mV
B
W
4.00ms
T
W
CH1
5.0V
14.0ms
12069-031
3
Figure 32. Inverting Regulator Line Transient, VIN = 4.5 V to 5.5 V Step,
VNEG = −15 V, RLOAD2 = 300 Ω, fSW = 2.4 MHz, TA = 25°C
Figure 29. Boost Regulator Line Transient, VIN = 4.5 V to 5.5 V Step,
VPOS = 15 V, RLOAD1 = 300 Ω, fSW = 2.4 MHz, TA = 25°C
T
T
ILOAD1
ILOAD2
VNEG
1
2
VPOS
2
1
VFB2
3
VFB1
CH3 25mV
CH2 50mV
B
W
B
W
4.00ms
T
CH1
13.160ms
137mA
CH1 10mA
12069-029
CH1 20mA
CH3 5mV
Figure 30. Boost Regulator Load Transient, VIN = 5 V Step, VPOS = 15 V,
ILOAD1 = 120 mA to 150 mA Step, fSW = 2.4 MHz, TA = 25°C
CH2 50mV
B
W
B
W
4.00ms
T
13.0ms
CH1
50mA
12069-032
3
Figure 33. Inverting Regulator Load Transient, VIN = 5 V Step, VNEG = −15 V,
ILOAD2 = 35 mA to 45 mA Step, fSW = 2.4 MHz, TA = 25°C
Rev. A | Page 12 of 27
Data Sheet
ADP5071
T
T
IINDUCTOR
IINDUCTOR
1
1
SW2
SW1
2
2
VNEG
VPOS
3
2.0µs
CH1
0.0A
T 34.6%
CH1 100mA BW CH2 5V Ω BW
CH3 500mV
Figure 34. Boost Regulator Skip Mode Operation Showing Inductor Current
(IINDUCTOR), Switch Node Voltage, and Output Ripple, VIN = 5 V,
VPOS = 15 V, ILOAD1 = 4 mA, fSW = 2.4 MHz, TA = 25°C
B
W
2.0µs
CH1
0A
T 17.4%
12069-036
CH1 200mA BW CH2 2.5V Ω BW
CH3 500mV BW
12069-033
3
Figure 37. Inverting Regulator Skip Mode Operation Showing Inductor
Current (IINDUCTOR), Switch Node Voltage, and Output Ripple, VIN = 5 V,
VNEG = −5 V, ILOAD2 = 1 mA, fSW = 2.4 MHz, TA = 25°C
T
T
IINDUCTOR
IINDUCTOR
1
1
SW2
SW1
2
2
VPOS
VNEG
3
CH3 500mV
B
CH1
152mA
T 34.6%
W
CH1 100mA BW CH2 5.0V Ω BW 100ns
CH3 500mV
Figure 35. Boost Regulator Discontinuous Conduction Mode Operation
Showing Inductor Current (IINDUCTOR), Switch Node Voltage, and Output
Ripple, VIN = 5 V, VPOS = 15 V, ILOAD1 = 35 mA, fSW = 2.4 MHz, TA = 25°C
B
W
CH1
80mA
T 17.4%
12069-037
CH1 200mA BW CH2 2.5V Ω BW 100ns
12069-034
3
Figure 38. Inverting Regulator Discontinuous Conduction Mode Operation
Showing Inductor Current (IINDUCTOR), Switch Node Voltage, and Output Ripple,
VIN = 5 V, VNEG = −5 V, ILOAD2 = 6 mA, fSW = 2.4 MHz, TA = 25°C
T
T
IINDUCTOR
1
1
IINDUCTOR
SW2
2
SW1
2
VNEG
3
3
CH1
152mA
CH1 100mA BW CH2 5V Ω BW
CH3 500mV
Figure 36. Boost Regulator Continuous Conduction Mode Operation
Showing Inductor Current (IINDUCTOR), Switch Node Voltage, and Output
Ripple, VIN = 5 V, VPOS = 15 V, ILOAD1 = 90 mA, fSW = 2.4 MHz, TA = 25°C
B
W
100ns
T 17.4%s
CH1
172mA
12069-038
CH1 200mA BW CH2 2.5V Ω BW 100ns
CH3 500mV BW
T 34.6%
12069-035
VPOS
Figure 39. Inverting Regulator Continuous Conduction Mode Operation
Showing Inductor Current (IINDUCTOR), Switch Node Voltage, and Output
Ripple, VIN = 5 V, VNEG = −5 V, ILOAD2 = 35 mA, fSW = 2.4 MHz, TA = 25°C
Rev. A | Page 13 of 27
ADP5071
Data Sheet
THEORY OF OPERATION
VIN
CVREG
PVIN1
PVINSYS
SYNC/FREQ
VREG
PVIN2
CURRENT SENSE
INBK SWITCH
CONTROL
HV
REGULATOR
INVERTER
PWM CONTROL
INBK
D2
SW2
L1
VOUT1
D1
EN1
SW1
SLEW
HV
BAND GAP
REF1
RC1
RFB2
INVERTER_ENABLE
REF_1V6
+
THERMAL
SHUTDOWN
1.5MΩ
COMP1
FB2
BOOST_ENABLE
SEQUENCE
CONTROL
ERROR
AMP
FB1
FB2
CC1
SLEW
EN1
COMP2
4µA
OVP
EN2 SEQ
VREF
CVREF
VREG
UVLO
RFT2
REF2
–
1.5MΩ
RFB1
–
ERROR
AMP
+
OSCILLATOR
CURRENT
SENSE
FB1
COUT2
PLL
BOOST PWM
CONTROL
PGND
L2
EN2
COUT1
RFT1
SLEW
START-UP
TIMERS
REFERENCE
GENERATOR
SS
RSS (OPTIONAL)
REF1
REF2
RC2
REF_1V6
CC2
AGND
12069-039
CIN
Figure 40. Functional Block Diagram
PWM MODE
The boost and inverting regulators in the ADP5071 operate at a
fixed frequency set by an internal oscillator. At the start of each
oscillator cycle, the MOSFET switch turns on, applying a positive
voltage across the inductor. The inductor current increases until
the current sense signal crosses the peak inductor current threshold
that turns off the MOSFET switch; this threshold is set by the error
amplifier output. During the MOSFET off time, the inductor
current declines through the external diode until the next
oscillator clock pulse starts a new cycle. It regulates the output
voltage by adjusting the peak inductor current threshold.
PSM MODE
During light load operation, the regulators can skip pulses to
maintain output voltage regulation. Skipping pulses increases
the device efficiency.
UNDERVOLTAGE LOCKOUT (UVLO)
The undervoltage lockout circuitry monitors the PVINSYS pin
voltage level. If the input voltage drops below the VUVLO_FALLING
threshold, both regulators turn off. After the PVINSYS pin voltage
rises above the VUVLO_RISING threshold, the soft start period initiates,
and the regulators are enabled.
OSCILLATOR AND SYNCHRONIZATION
The ADP5071 initiates the drive of the boost regulator SW1 pin
and the inverting regulator SW2 pin 180° out of phase to reduce
peak current consumption and noise.
A phase-locked loop (PLL)-based oscillator generates the internal
clock and offers a choice of two internally generated frequency
options or external clock synchronization. The switching frequency
is configured using the SYNC/FREQ pin options shown in Table 6.
For external synchronization, connect the SYNC/FREQ pin to a
suitable clock source. The PLL locks to an input clock within
the range specified by fSYNC.
Table 6. SYNC/FREQ Pin Options
SYNC/FREQ Pin
High
Low
External Clock
Switching Frequency
2.4 MHz
1.2 MHz
1 × clock frequency
INTERNAL REGULATORS
The internal VREG regulator in the ADP5071 provides a stable
power supply for the internal circuitry. The VREG supply can be
used to provide a logic high signal for device configuration pins but
must not be used to supply external circuitry.
The VREF regulator provides a reference voltage for the inverting
regulator feedback network to ensure a positive feedback voltage on
the FB2 pin.
A current-limit circuit is included for both regulators to protect the
circuit from accidental loading.
Rev. A | Page 14 of 27
Data Sheet
ADP5071
PRECISION ENABLING
CURRENT-LIMIT PROTECTION
The ADP5071 has an individual enable pin for the boost and
inverting regulators: EN1 and EN2. The enable pins feature a
precision enable circuit with an accurate reference voltage. This
reference allows the ADP5071 to be sequenced easily from other
supplies. It can also be used as a programmable UVLO input by
using a resistor divider.
The boost and inverting regulators in the ADP5071 include
current-limit protection circuitry to limit the amount of forward
current through the MOSFET switch.
The enable pins have an internal pull-down resistor that defaults
each regulator to off when the pin is floating.
When the voltage at the enable pins is greater than the VTH_H
reference level, the regulator is enabled.
When the peak inductor current exceeds the overcurrent limit
threshold for a number of clock cycles during an overload or
short-circuit condition, the regulator enters hiccup mode. The
regulator stops switching and then restarts with a new soft start
cycle after tHICCUP and repeats until the overcurrent condition is
removed.
OVERVOLTAGE PROTECTION
SOFT START
Each regulator in the ADP5071 includes soft start circuitry that
ramps the output voltage in a controlled manner during startup,
thereby limiting the inrush current. The soft start time is internally
set to the fastest rate when the SS pin is open.
Connecting a resistor between SS and AGND allows the adjustment of the soft start delay. The delay length is common to both
regulators.
SLEW RATE CONTROL
The ADP5071 employs programmable output driver slew rate
control circuitry. This circuitry reduces the slew rate of the
switching node as shown in Figure 41, resulting in reduced
ringing and lower EMI. To program the slew rate, connect the
SLEW pin to the VREG pin for normal mode, to the AGND pin
for slow mode, or leave it open for fast mode. This configuration
allows the use of an open-drain output from a noise sensitive
device to switch the slew rate from fast to slow, for example,
during analog-to-digital converter (ADC) sampling.
Note that slew rate control causes a trade-off between efficiency
and low EMI.
An overvoltage protection mechanism is present on the FB1
and FB2 pins for the boost and inverting regulators.
On the boost regulator, when the voltage on the FB1 pin exceeds
the VOV1 threshold, the switching on SW1 stops until the voltage
falls below the threshold again. This functionality is permanently
enabled on this regulator.
On the inverting regulator, when the voltage on the FB2 pin
drops below the VOV2 threshold, the switching stops until the
voltage rises above the threshold. This functionality is enabled
after the soft start period has elapsed.
THERMAL SHUTDOWN
In the event that the ADP5071 junction temperature rises above
TSHDN, the thermal shutdown circuit turns off the IC. Extreme
junction temperatures can be the result of prolonged high current
operation, poor circuit board design, and/or high ambient temperature. Hysteresis is included so that when thermal shutdown occurs,
the ADP5071 does not return to operation until the on-chip
temperature drops below TSHDN minus THYS. When resuming from
thermal shutdown, a soft start is performed on each enabled
channel.
START-UP SEQUENCE
The ADP5071 implements a flexible start-up sequence to meet
different system requirements. Three different enabling modes
can be implemented via the SEQ pin, as explained in Table 7.
FASTEST
Table 7. SEQ Pin Settings
12069-040
SLOWEST
Figure 41. Switching Node at Various Slew Rate Settings
SEQ Pin
Open
VREG
Low
Description
Manual enable mode
Simultaneous enable mode
Sequential enable mode
To configure the manual enable mode, leave the SEQ pin open.
The boost and inverting regulators are controlled separately from
their respective precision enable pins.
Rev. A | Page 15 of 27
ADP5071
Data Sheet
To configure the simultaneous enable mode, connect the SEQ pin
to the VREG pin. Both regulators power up simultaneously
when the EN2 pin is taken high. The EN1 pin enable can be
used to enable the internal references ahead of enabling the
outputs, if desired. The simultaneous enable mode timing is
shown in Figure 42.
VPOS
VIN
DISCONNECT
SWITCH TURN ON
VPOS
TIME
VNEG
1. VPOS FOLLOWED BY VNEG
(SEQ = LOW, EN1 = HIGH, EN2 = LOW)
VIN
DISCONNECT
SWITCH TURN ON
VPOS
TIME
VIN
DISCONNECT
SWITCH TURN ON
SIMULTANEOUS ENABLE MODE
(SEQ = HIGH, EN2 = HIGH)
12069-041
VNEG
TIME
Figure 42. Simultaneous Enable Mode
Rev. A | Page 16 of 27
VNEG
2. VNEG FOLLOWED BY VPOS
(SEQ = LOW, EN2 = HIGH, EN1 = LOW)
SEQUENTIAL ENABLE MODE
Figure 43. Sequential Enable Mode
12069-042
To configure the sequential enable mode, pull the SEQ pin low.
In this mode, either VPOS or VNEG can be enabled first by using
the respective EN1 pin or EN2 pin. Keep the other pin low. The
secondary supply is enabled when the primary supply completes
soft start and its feedback voltage reaches approximately 85% of
the target value. The sequential enable mode timing is shown in
Figure 43.
Data Sheet
ADP5071
APPLICATIONS INFORMATION
ADIsimPOWER DESIGN TOOL
Set the positive output for the boost regulator by
The ADP5071 is supported by the ADIsimPower design toolset.
ADIsimPower is a collection of tools that produce complete
power designs optimized to a specific design goal. These tools
allow the user to generate a full schematic, bill of materials, and
calculate performance in minutes. ADIsimPower can optimize
designs for cost, area, efficiency, and parts count while taking
into consideration the operating conditions and limitations of
the IC and all real external components. The ADIsimPower tool
can be found at www.analog.com/adisimpower, and the user
can request an unpopulated board through the tool.
 RFT1 
VPOS = VFB1 × 1 +

 RFB1 
where:
VPOS is the positive output voltage.
VFB1 is the FB1 reference voltage.
RFT1 is the feedback resistor from VPOS to FB1.
RFB1 is the feedback resistor from FB1 to AGND.
Set the negative output for the inverting regulator by
COMPONENT SELECTION
VNEG = VFB2 −
Feedback Resistors
The ADP5071 provides an adjustable output voltage for both boost
and inverting regulators. An external resistor divider sets the output
voltage where the divider output must equal the appropriate
feedback reference voltage, VFB1 or VFB2. To limit the output voltage
accuracy degradation due to feedback bias current, ensure that the
current through the divider is at least 10 times IFB1 or IFB2.
RFT2
(VREF − VFB2 )
RFB2
where:
VNEG is the negative output voltage.
VFB2 is the FB2 reference voltage.
RFT2 is the feedback resistor from VNEG to FB2.
RFB2 is the feedback resistor from FB2 to VREF.
VREF is the VREF pin reference voltage.
Table 8. Recommended Feedback Resistor Values
Desired Output
Voltage (V)
±1.8
±3
±3.3
±4.2
±5
±9
±12
±13
±15
±18
±20
±24
±30
±35
RFT1 (MΩ)
0.143
0.316
0.357
0.432
0.604
1.24
1.4
2.1
2.43
2.15
2.55
3.09
3.65
5.9
Boost/SEPIC Regulator
Calculated
RFB1 (kΩ)
Output Voltage (V)
115
1.795
115
2.998
115
3.283
102
4.188
115
5.002
121
8.998
100
12.000
137
13.063
137
14.990
100
18.000
107
19.865
107
23.903
100
30.000
137
35.253
Rev. A | Page 17 of 27
RFT2 (MΩ)
0.332
0.475
0.523
0.715
1.15
1.62
1.15
2.8
2.32
2.67
2.94
3.16
4.12
5.11
Inverting Regulator
Calculated
RFB2 (kΩ)
Output Voltage (V)
102
−1.804
100
−3.000
102
−3.302
115
−4.174
158
−5.023
133
−8.944
71.5
−12.067
162
−13.027
118
−14.929
113
−18.103
113
−20.014
102
−23.984
107
−30.004
115
−34.748
ADP5071
Data Sheet
Output Capacitors
VREF Capacitor
Higher output capacitor values reduce the output voltage ripple
and improve load transient response. When choosing this value,
it is also important to account for the loss of capacitance due to
the output voltage dc bias.
A 1.0 µF ceramic capacitor (CVREF) is required between the VREF
pin and AGND.
Calculate the worst-case capacitance accounting for capacitor
variation over temperature, component tolerance, and voltage
using the following equation:
A resistor can be connected between the SS pin and the AGND pin
to increase the soft start time. The soft start time can be set by the
resistor between 4 ms (268 kΩ) and 32 ms (50 kΩ). Leaving the
SS pin open selects the fastest time of 4 ms. Figure 44 shows the
behavior of this operation. Calculate the soft start time using the
following formula:
tSS = 38.4 × 10−3 − 1.28 × 10−7 × RSS (Ω)
where 50 kΩ ≤ RSS ≤ 268 kΩ.
SOFT START
TIMER
32ms
CEFFECTIVE = CNOMINAL × (1 − TEMPCO) × (1 − DCBIASCO) ×
(1 − Tolerance)
where:
CEFFECTIVE is the effective capacitance at the operating voltage.
CNOMINAL is the nominal data sheet capacitance.
TEMPCO is the worst-case capacitor temperature coefficient.
DCBIASCO is the dc bias derating at the output voltage.
Tolerance is the worst-case component tolerance.
To guarantee the performance of the device, it is imperative that
the effects of dc bias, temperature, and tolerances on the
behavior of the capacitors be evaluated for each application.
Capacitors with lower effective series resistance (ESR) and
effective series inductance (ESL) are preferred to minimize
output voltage ripple.
Note that the use of large output capacitors can require a slower
soft start to prevent current limit during startup. A 10 µF capacitor
is suggested as a good balance between performance and size.
Input Capacitor
Higher value input capacitors help to reduce the input voltage
ripple and improve transient response.
To minimize supply noise, place the input capacitor as close as
possible to the PVINSYS pin, PVIN1 pin, and PVIN2 pin. A low
ESR capacitor is recommended.
The effective capacitance needed for stability is a minimum of 10 µF.
If the power pins are individually decoupled, it is recommended
to use an effective minimum of a 5.6 µF capacitor on the PVIN1
and PVIN2 pins and a 3.3 µF capacitor on the PVINSYS pin. The
minimum values specified exclude dc bias, temperature, and
tolerance effects that are application dependent and must be
taken into consideration.
4ms
SS PIN OPEN
R2
R1
SOFT START
RESISTOR
12069-043
Ceramic capacitors are manufactured with a variety of dielectrics,
each with a different behavior over temperature and applied
voltage. Capacitors must have a dielectric adequate to ensure the
minimum capacitance over the necessary temperature range and
dc bias conditions. X5R or X7R dielectrics with a voltage rating of
25 V or 50 V (depending on output) are recommended for best
performance. Y5V and Z5U dielectrics are not recommended
for use with any dc-to-dc converter because of their poor
temperature and dc bias characteristics.
Soft Start Resistor
Figure 44. Soft Start Behavior
Diodes
A Schottky diode with low junction capacitance is recommended
for D1 and D2. At higher output voltages and especially at higher
switching frequencies, the junction capacitance is a significant
contributor to efficiency. Higher capacitance diodes also generate
more switching noise. As a guide, a diode with less than 40 pF
junction capacitance is preferred when the output voltage is
above 5 V.
Inductor Selection for the Boost Regulator
The inductor stores energy during the on time of the power
switch, and transfers that energy to the output through the
output rectifier during the off time. To balance the tradeoffs
between small inductor current ripple and efficiency, inductance
values in the range of 1 µH to 22 µH are recommended. In general,
lower inductance values have higher saturation current and
lower series resistance for a given physical size. However, lower
inductance results in a higher peak current that can lead to reduced
efficiency and greater input and/or output ripple and noise. A
peak-to-peak inductor ripple current close to 30% of the maximum
dc input current for the application typically yields an optimal
compromise.
VREG Capacitor
A 1.0 µF ceramic capacitor (CVREG) is required between the VREG
pin and AGND.
Rev. A | Page 18 of 27
Data Sheet
ADP5071
For the inductor ripple current in continuous conduction mode
(CCM) operation, the input (VIN) and output (VPOS) voltages
determine the switch duty cycle (DUTY1) by the following
equation:
 V − VIN + VDIODE1 

DUTY1 =  POS
 VPOS + VDIODE1 


where VDIODE1 is the forward voltage drop of the Schottky diode
(D1).
The dc input current in CCM (IIN) can be determined by the
following equation:
I IN =
I OUT1
(1 − DUTY1)
Using the duty cycle (DUTY1) and switching frequency (fSW),
determine the on time (tON1) using the following equation:
t ON1 =
DUTY1
f SW
Inductor Selection for the Inverting Regulator
The inductor stores energy during the on time of the power
switch, and transfers that energy to the output through the
output rectifier during the off time. To balance the tradeoffs
between small inductor current ripple and efficiency, inductance
values in the range of 1 µH to 22 µH are recommended. In
general, lower inductance values have higher saturation current
and lower series resistance for a given physical size. However,
lower inductance results in a higher peak current that can lead
to reduced efficiency and greater input and/or output ripple and
noise. A peak-to-peak inductor ripple current close to 30% of
the maximum dc current in the inductor typically yields an
optimal compromise.
For the inductor ripple current in continuous conduction mode
(CCM) operation, the input (VIN) and output (VNEG) voltages
determine the switch duty cycle (DUTY2) by the following
equation:
 | VNEG | + VDIODE2 

DUTY2 = 
 V + | V | + VDIODE2 
IN
NEG


The inductor ripple current (∆IL1) in steady state is calculated by
∆I L1 =
where VDIODE2 is the forward voltage drop of the Schottky diode
(D2).
VIN × tON1
L1
Solve for the inductance value (L1) using the following equation:
L1 =
VIN × tON1
∆I L1
I L2 =
Assuming an inductor ripple current of 30% of the maximum
dc input current results in
L1 =
The dc current in the inductor in CCM (IL2) can be determined
by the following equation:
VIN × t ON1 × (1 − DUTY1)
I OUT2
(1 − DUTY2)
Using the duty cycle (DUTY2) and switching frequency (fSW),
determine the on time (tON2) by the following equation:
t ON2 =
0.3 × IOUT1
Ensure that the peak inductor current (the maximum input
current plus half the inductor ripple current) is below the rated
saturation current of the inductor. Likewise, ensure that the
maximum rated rms current of the inductor is greater than the
maximum dc input current to the regulator.
When the ADP5071 boost regulator is operated in CCM at duty
cycles greater than 50%, slope compensation is required to stabilize
the current mode loop. This slope compensation is built in to
the ADP5071 For stable current mode operation, ensure that
the selected inductance is equal to or greater than the minimum
calculated inductance, LMIN1, for the application parameters in
the following equation:


0.13
− 0.16  (µH)
L1 > L MIN1 = VIN × 
 (1 − DUTY1)



Table 10 suggests a series of inductors to use with the ADP5071
boost regulator.
DUTY2
f SW
The inductor ripple current (∆IL2) in steady state is calculated by
∆I L2 =
VIN × tON2
L2
Solve for the inductance value (L2) by the following equation:
L2 =
VIN × tON2
∆I L2
Assuming an inductor ripple current of 30% of the maximum
dc current in the inductor results in
L2 =
VIN × t ON2 × (1 − DUTY2)
0.3 × IOUT2
Ensure that the peak inductor current (the maximum input current
plus half the inductor ripple current) is below the rated saturation
current of the inductor. Likewise, ensure that the maximum rated
rms current of the inductor is greater than the maximum dc
input current to the regulator.
Rev. A | Page 19 of 27
ADP5071
Data Sheet
When the ADP5071 inverting regulator is operated in CCM at
duty cycles greater than 50%, slope compensation is required to
stabilize the current mode loop. For stable current mode operation,
ensure that the selected inductance is equal to or greater than
the minimum calculated inductance, LMIN2, for the application
parameters in the following equation:
Table 11 suggests a series of inductors to use with the ADP5071
inverting regulator.
To determine the crossover frequency (fC1), it is important to
note that, at that frequency, the compensation impedance (ZCOMP1)
is dominated by a resistor (RC1), and the output impedance (ZOUT1)
is dominated by the impedance of an output capacitor (COUT1).
Therefore, when solving for the crossover frequency, the equation
(by definition of the crossover frequency) is simplified to
VFB1 VIN
×
× G M1 × RC1 × GCS1 ×
VPOS VPOS
1
=1
2π × f C1 × COUT1
LOOP COMPENSATION
The ADP5071 uses external components to compensate the
regulator loop, allowing the optimization of the loop dynamics
for a given application. It is recommended to use the ADIsimPower
tool to calculate compensation components.
Boost Regulator
The boost converter produces an undesirable right half plane
zero in the regulation feedback loop. This feedback loop requires
compensating the regulator such that the crossover frequency
occurs well below the frequency of the right half plane zero. The
right half plane zero is determined by the following equation:
f Z1 (RHP ) =
AVL1 =
where fC1 is the crossover frequency.
To solve for RC1, use the following equation:
RC1 =
VFB1 × VIN × G M1 × GCS1
where GCS1 = 12.5 A/V.
Using typical values for VFB1 and GM1 results in
RLOAD1 (1 − DUTY1)2
2π × L1
RC1 =
where:
fZ1(RHP) is the right half plane zero frequency.
RLOAD1 is the equivalent load resistance or the output voltage
divided by the load current.
2094 × f C1 × COUT1 × (VPOS )2
VIN
For better accuracy, it is recommended to use the value of output
capacitance, COUT1, expected for the dc bias conditions under
which it operates under in the calculation for RC1.
 V − VIN + VDIODE1 

DUTY1 =  POS
 VPOS + VDIODE1 


After the compensation resistor is known, set the zero formed
by the compensation capacitor and resistor to one-fourth of the
crossover frequency, or
where VDIODE1 is the forward voltage drop of the Schottky
diode (D1).
To stabilize the regulator, ensure that the regulator crossover
frequency is less than or equal to one-tenth of the right half
plane zero frequency.
CC1 =
2
π × f C1 × RC1
where CC1 is the compensation capacitor value.
FB1
The boost regulator loop gain is
AVL1 =
2π × f C1 × COUT1 × (VPOS )2
ERROR
AMPLIFIER
COMP1
gM1
VFB1 VIN
×
× G M1 × ROUT1|| Z COMP1 × GCS1 × ZOUT1
VPOS VPOS
where:
AVL1 is the loop gain.
VFB1 is the feedback regulation voltage
VPOS is the regulated positive output voltage.
VIN is the input voltage.
GM1 is the error amplifier transconductance gain.
ROUT1 is the output impedance of the error amplifier and is 33 MΩ.
ZCOMP1 is the impedance of the series RC network from
COMP1 to AGND.
REF1
RC1
CB1
CC1
12069-044
L2 > L MIN2


0.13
= VIN × 
− 0.16  (µH)
 (1 − DUTY2)



GCS1 is the current sense transconductance gain (the inductor
current divided by the voltage at COMP1), which is internally
set by the ADP5071and is 12.5 A/V.
ZOUT1 is the impedance of the load in parallel with the output
capacitor.
Figure 45. Compensation Components
The capacitor, CB1, is chosen to cancel the zero introduced by
the output capacitor ESR. Solve for CB1 as follows:
Rev. A | Page 20 of 27
CB1 =
ESR × COUT1
RC1
Data Sheet
ADP5071
For low ESR output capacitance such as with a ceramic capacitor,
CB1 is optional. For optimal transient performance, RC1 and CC1
may need to be adjusted by observing the load transient response
of the ADP5071. For most applications, RC1 must be within the
range of 1 kΩ to 200 kΩ, and CC1 must be within the range of
1 nF to 68 nF.
To determine the crossover frequency, it is important to note
that, at that frequency, the compensation impedance (ZCOMP2) is
dominated by a resistor, RC2, and the output impedance (ZOUT2)
is dominated by the impedance of the output capacitor, COUT2.
Therefore, when solving for the crossover frequency, the equation
(by definition of the crossover frequency) is simplified to
Inverting Regulator
The inverting converter, like the boost converter, produces an
undesirable right half plane zero in the regulation feedback loop.
This feedback loop requires compensating the regulator such that
the crossover frequency occurs well below the frequency of the
right half plane zero. The right half plane zero frequency is
determined by the following equation:
f Z2(RHP) =
VFB2
VIN
×
× GM2 ×
|VNEG| (VIN + 2 × | VNEG|)
RC2 × GCS 2 ×
1
=1
2π × fC2 × COUT2
where fC2 is the crossover frequency.
To solve for RC2, use the following equation:
RLOAD2( 1 − DUTY2)
2π × L2 × DUTY2
2
RC2 =
2π × fC2 × COUT2 × |VNEG| × (VIN + (2 × | VNEG|)
VFB2 × VIN × GM2 × GCS2
where GCS2 = 12.5 A/V.
where:
fZ2(RHP) is the right half plane zero frequency.
RLOAD2 is the equivalent load resistance or the output voltage
divided by the load current.
Using typical values for VFB2 and GM2 results in
RC2 =
 |VNEG| + VDIODE2 

DUTY2 = 

 VIN + |VNEG| + VDIODE2 
where VDIODE2 is the forward voltage drop of the Schottky diode
(D2).
To stabilize the regulator, ensure that the regulator crossover
frequency is less than or equal to one-tenth of the right half
plane zero frequency.
The inverting regulator loop gain is
AVL2 =
AVL2 =
2094 × fC2 × COUT2 × | VNEG| × (VIN + (2 × | VNEG|)
VIN
For better accuracy, it is recommended to use the value of output
capacitance, COUT2, expected under the dc bias conditions that it
operates under in the calculation for RC2.
After the compensation resistor is known, set the zero formed
by the CC2 and RC2 to one-fourth of the crossover frequency, or
CC2 =
2
π × f C2 × RC2
where CC2 is the compensation capacitor.
VIN
VFB2
×
× GM2 ×
|VNEG| (VIN + 2 × | VNEG|)
FB2
ERROR
AMPLIFIER
COMP2
gM2
ROUT2|| Z COMP2 × GCS2 × Z OUT2
RC2
CB2
CC2
where:
AVL2 is the loop gain.
VFB2 is the feedback regulation voltage.
VNEG is the regulated negative output voltage.
VIN is the input voltage.
GM2 is the error amplifier transconductance gain.
ROUT2 is the output impedance of the error amplifier and is 33 MΩ.
ZCOMP2 is the impedance of the series RC network from COMP2
to AGND.
GCS2 is the current sense transconductance gain (the inductor
current divided by the voltage at COMP2), which is internally
set by the ADP5071 and is 12.5 A/V.
ZOUT2 is the impedance of the load in parallel with the output
capacitor.
12069-045
REF2
Figure 46. Compensation Component
The capacitor, CB2, is chosen to cancel the zero introduced by
output capacitance, ESR.
Solve for CB2 as follows:
CB2 =
ESR × C OUT2
RC2
For low ESR output capacitance, such as with a ceramic capacitor,
CB2 is optional. For optimal transient performance, RC2 and CC2
may need to be adjusted by observing the load transient response
of the ADP5071. For most applications, RC2 must be within the
range of 1 kΩ to 200 kΩ, and CC2 must be within the range of
1 nF to 68 nF.
Rev. A | Page 21 of 27
ADP5071
Data Sheet
COMMON APPLICATIONS
Figure 47 shows the schematic referenced by Table 9 through
Table 11 with example component values for +5 V to ±15 V
generation. Table 9 shows the components common to all of the
VIN and VOUT conditions.
Table 9 through Table 11 list a number of common component
selections for typical VIN and VOUT conditions. These have been
bench tested and provide an off the shelf solution. Note that when
pairing a boost and inverting regulator bill of materials, choose
the same VIN and switching frequency. To optimize components
for an application, it is recommend to use the ADIsimPower
toolset.
Table 9. Recommended Common Components Selections
REF
CIN1
CVREG
CVREF
Value
10 µF
1 µF
1 μF
Part Number
TMK316B7106KL-TD
GRM188R71A105KA61D
GRM188R71A105KA61D
ADP5071
SS
INBK
CC1
47nF
VREG
VIN
+5V
CIN1
10µF
RC2
12kΩ
CC2
47nF
VPOS
+15V
SW1
EN1
CVREG
1µF
L1
3.3µH
D1
DFLS240
COMP1
FB1
RFT1
2.43MΩ
RFB1
137kΩ
PVIN1
PVIN2
PVINSYS
PGND
EN2
VREF
CVREF
1µF
RFB2
118kΩ
COMP2
SYNC/FREQ
SLEW
SEQ
AGND
FB2
COUT2
10µF
RFT2
2.32MΩ
SW2
D2
DFLS240
L2
6.8µH
Figure 47. Typical +5 V to ±15 V Application
Rev. A | Page 22 of 27
COUT1
10µF
VNEG
–15V
12069-046
RC1
5.6kΩ
Manufacturer
Taiyo Yuden
Murata
Murata
Data Sheet
ADP5071
Table 10. Recommended Boost Regulator Components
VIN
(V)
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
5
5
5
5
5
5
5
5
12
12
VPOS
(V)
5
5
9
9
15
15
24
24
34
34
9
9
15
15
24
24
34
34
24
24
Freq.
(MHz)
1.2
2.4
1.2
2.4
1.2
2.4
1.2
2.4
1.2
2.4
1.2
2.4
1.2
2.4
1.2
2.4
1.2
2.4
1.2
2.4
L1
(µH)
2.2
1
2.2
1.5
3.3
1.5
3.3
3.3
4.7
4.7
3.3
1.5
3.3
2.2
4.7
3.3
4.7
4.7
6.8
3.3
L1, Coilcraft®
Part
XAL4020-222ME_
XAL4020-102ME_
XAL4020-222ME_
XAL4020-152ME_
XAL4030-332ME_
XAL4020-152ME_
XAL4030-332ME_
XAL4030-332ME_
XAL4030-472ME_
XAL4030-472ME_
XAL4030-332ME_
XAL4020-152ME_
XAL4030-332ME_
XAL4020-222ME_
XAL4030-472ME_
XAL4030-332ME_
XAL4030-472ME_
XAL4030-472ME_
XAL4030-682ME_
XAL4030-332ME_
COUT1
(µF)
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
COUT1, Murata Part
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
D1, Diodes,
Inc. Part
DFLS240L
DFLS240L
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
RFT1
(MΩ)
0.604
0.604
1.24
1.24
2.43
2.43
3.09
3.09
4.22
4.22
1.24
1.24
2.43
2.43
3.09
3.09
4.22
4.22
3.09
3.09
RFB1
(kΩ)
115
115
121
121
137
137
107
107
102
102
121
121
137
137
107
107
102
102
107
107
CC1
(nF)
47
47
47
47
47
47
47
47
47
47
47
47
47
47
47
47
47
47
47
47
RC1
(kΩ)
4.7
4.7
3.3
3.3
14
14
18
18
33
33
1.8
2.2
5.6
8.2
10
10
12
12
4.7
4.7
D2, Diodes,
Inc. Part
DFLS240L
DFLS240L
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
DFLS240
RFT2
(MΩ)
1.15
1.15
1.62
1.62
2.32
2.32
3.16
3.16
4.99
4.99
1.62
1.62
2.32
2.32
3.16
3.16
4.99
4.99
3.16
3.16
RFB2
(kΩ)
158
158
133
133
118
118
102
102
115
115
133
133
118
118
102
102
115
115
102
102
CC2
(nF)
47
47
47
47
47
47
47
47
47
47
47
47
68
47
47
47
47
47
47
47
RC2
(kΩ)
8.2
8.2
10
15
18
18
39
47
33
33
5.6
5.6
12
12
27
27
39
39
15
15
Table 11. Recommended Inverting Regulator Components
VIN
(V)
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
5
5
5
5
5
5
5
5
12
12
VNEG
(V)
−5
−5
−9
−9
−15
−15
−24
−24
−34
−34
−9
−9
−15
−15
−24
−24
−34
−34
−24
−24
Freq.
(MHz)
1.2
2.4
1.2
2.4
1.2
2.4
1.2
2.4
1.2
2.4
1.2
2.4
1.2
2.4
1.2
2.4
1.2
2.4
1.2
2.4
L2
(µH)
3.3
2.2
4.7
2.2
4.7
2.2
4.7
3.3
6.8
4.7
6.8
3.3
6.8
3.3
10
4.7
10
4.7
15
6.8
L2, Coilcraft Part
XAL4030-332ME_
XAL4020-222ME_
XAL4030-472ME_
XAL4020-222ME_
XAL4030-472ME_
XAL4020-222ME_
XAL4030-472ME_
XAL4030-332ME_
XAL4030-682ME_
XAL4030-472ME_
XAL4030-682ME_
XAL4030-332ME_
XAL4030-682ME_
XAL4030-332ME_
XAL4040-103ME_
XAL4030-472ME_
XAL4040-103ME_
XAL4030-472ME_
XAL4040-153ME_
XAL4030-682ME_
COUT2
(µF)
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
COUT2, Murata Part
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
GRM32ER71H106KA12L
Rev. A | Page 23 of 27
ADP5071
Data Sheet
SUPER LOW NOISE WITH OPTIONAL LDOS
Low dropout regulators (LDOs) can be added to the ADP5071
output to provide super low noise supplies for high performance
ADCs, digital-to-analog converters (DACs), and other precision
applications. Table 12 shows recommended companion devices,
and Figure 48 shows a typical application schematic for ±15 V
generation from a +5 V supply.
ADP5071
SS
INBK
D1
DFLS240
COMP1
CC1
47nF
FB1
VREG
VIN
+5V
CIN1
10µF
RC2
12kΩ
CC2
47nF
RFT1
2.15MΩ
RFB1
113kΩ
PVIN1
PVIN2
PVINSYS
PGND
EN2
VREF
VOUT
ADJ
(5V)
COUT1
10µF
SS
VPOS = +15V
RFT3
20kΩ
RFB3
10kΩ
CNR3
1µF
RNR3
1kΩ
COUT3
2.2µF
GND
CSS3
1nF
CVREF
1µF
FB2
SYNC/FREQ
SLEW
SEQ
AGND
CIN3
1µF
VIN
EN
ADP7182
COUT2
10µF
RFB2
100kΩ
COMP2
ADP7142
+16V
SW1
EN1
CVREG
1µF
L1
3.3µH
RFT2
2.1MΩ
SW2
EN
VOUT
ADJ
–16V
D2
DFLS240
CIN4
2.2µF
VIN
GND
VNEG = –15V
RFT4
52.3kΩ
RFB4
5.9kΩ
CNR4
47µF
RNR4
5.9kΩ
COUT4
2.2µF
12069-047
RC1
5.6kΩ
L2
6.8µH
Figure 48. Super Low Noise ±15 V Generation with Post Regulation by the ADP7142 (+40 V, +200 mA, Low Noise LDO) and ADP7182 (−28 V, −200 mA, Low Noise LDO)
Table 12. Recommended LDOs for Super Low Noise Operation
Parameter
VIN Range
Fixed VOUT
Adjustable VOUT
IOUT
IQ at No Load
ISHDN Typical
Soft Start
PGOOD
Noise (Fixed), 10 Hz
to 100 kHz
PSRR (100 kHz)
PSRR (1 MHz)
Package
ADP7102
3.3 V to 20 V
1.5 V to 9 V
1.22 V to 19 V
300 mA
400 µA
40 µA
No
Yes
15 µV rms
ADP7104
3.3 V to 20 V
1.5 V to 9 V
1.22 V to 19 V
500 mA
400 µA
40 µA
No
Yes
15 µV rms
ADP7105
3.3 V to 20 V
1.8 V, 3.3 V, 5 V
1.22 V to 19 V
500 mA
400 µA
40 µA
Yes
Yes
15 µV rms
ADP7118
2.7 V to 20 V
1.2 V to 5 V
1.2 V to 19 V
200 mA
50 µA
2 µA
Yes
No
11 µV rms
ADP7142
2.7 V to 40 V
1.2 V to 5 V
1.2 V to 39 V
200 mA
50 µA
2 µA
Yes
No
11 µV rms
ADP7182
−2.7 V to −28 V
−1.8 V to −5 V
−1.22 V to−27 V
−200 mA
−33 µA
−2 µA
No
No
18 µV rms
60 dB
40 dB
8-lead LFCSP,
8-lead SOIC
60 dB
40 dB
8-lead LFCSP,
8-lead SOIC
60 dB
40 dB
8-lead LFCSP,
8-lead SOIC
68 dB
50 dB
6-lead LFCSP,
8-lead SOIC,
5-lead TSOT
68 dB
50 dB
6-lead LFCSP,
8-lead SOIC,
5-lead TSOT
45 dB
45 dB
6-lead LFCSP, 8-lead
LFCSP, 5-lead TSOT
Rev. A | Page 24 of 27
Data Sheet
ADP5071
SEPIC STEP-UP/STEP-DOWN OPERATION
SEPIC operation allows the positive output channel to produce
a voltage higher or lower than VIN. Both standalone and coupled
inductors are supported for this application. SEPIC designs are
supported in the ADIsimPower toolset.
ADP5071
SS
INBK
RC1
L1A
L1B
CS1
RFT1
D1
STANDALONE OR
COUPLED-INDUCTOR
COMP1
+5V/400mA
CC1
SW1
CVREG
VREG
1µF
VIN = +12V
CIN1
10µF
FB1
COUT1
RFB1
PVIN1
PVIN2
PVINSYS
PGND
EN2
VREF
CVREF
RFB2 1µF
RC2
COMP2
FB2
CC2
SYNC/FREQ
SLEW
SEQ
AGND
COUT2
RFT2
SW2
D2
–5V/400mA
L2
Figure 49. SEPIC Application for +12 V in to ±5 V Output Generation
Rev. A | Page 25 of 27
12069-048
EN1
ADP5071
Data Sheet
LAYOUT CONSIDERATIONS
Layout is important for all switching regulators but is particularly
important for regulators with high switching frequencies. To
achieve high efficiency, good regulation, good stability, and low
noise, a well-designed PCB layout is required. Follow these
guidelines when designing PCBs:
•
•
•
•
•
•
•
•
•
Keep the input bypass capacitor, CIN1, close to the PVIN1 pin,
the PVIN2 pin, and the PVINSYS pin. Route each of these
pins individually to the pad of this capacitor to minimize noise
coupling between the power inputs rather than connecting the
three pins at the device. A separate capacitor can be used on
the PVINSYS pin for the best noise performance.
Keep the high current paths as short as possible. These
paths include the connections between CIN1, L1, L2, D1,
D2, COUT1, COUT2, and PGND and their connections to
the ADP5071.
Keep AGND and PGND separate on the top layer of the
board. This separation avoids pollution of AGND with
switching noise. Do not connect PGND to the EPAD on
the top layer of the layout. Connect both AGND and PGND
to the board ground plane with vias. Ideally, connect PGND
to the plane at a point between the input and output
capacitors. Connect the EPAD on its own to this ground
layer with vias and connect AGND as near to the pin as
possible between the CVREF and CVREG capacitors.
Keep high current traces as short and wide as possible to
minimize parasitic series inductance, which causes spiking
and electromagnetic interference (EMI).
Avoid routing high impedance traces near any node connected to the SW1 and SW2 pins or near Inductors L1and
L2 to prevent radiated switching noise injection.
Place the feedback resistors as close to the FB1 and FB2 pins as
possible to prevent high frequency switching noise injection.
Place the top of the upper feedback resistors, RFT1 and RFT2,
or route traces to them from as close as possible to the top
of COUT1 and COUT2 for optimum output voltage sensing.
Place the compensation components as close as possible
to COMP1 and COMP2. Do not share vias to the ground
plane with the feedback resistors to avoid coupling high
frequency noise into the sensitive COMP1 and COMP2 pins.
Place the CVREF and CVREG capacitors as close to the
VREG and VREF pins as possible. Ensure that short traces
are used between VREF and RFB2.
Figure 50. Suggested LFCSP Layout; Vias Connected to the PCB Ground
Plane, Not to Scale
Figure 51. Suggested TSSOP Layout; Vias Connected to the PCB Ground
Plane, Not to Scale
Rev. A | Page 26 of 27
Data Sheet
ADP5071
OUTLINE DIMENSIONS
PIN 1
INDICATOR
0.30
0.25
0.18
0.50
BSC
PIN 1
INDICATOR
20
16
15
1
EXPOSED
PAD
2.75
2.60 SQ
2.35
11
TOP VIEW
0.80
0.75
0.70
5
BOTTOM VIEW
0.05 MAX
0.02 NOM
COPLANARITY
0.08
0.20 REF
SEATING
PLANE
6
10
0.50
0.40
0.30
0.25 MIN
FOR PROPER CONNECTION OF
THE EXPOSED PAD, REFER TO
THE PIN CONFIGURATION AND
FUNCTION DESCRIPTIONS
SECTION OF THIS DATA SHEET.
020509-B
4.10
4.00 SQ
3.90
COMPLIANT TO JEDEC STANDARDS MO-220-WGGD.
Figure 52. 20-Lead Lead Frame Chip Scale Package [LFCSP_WQ]
4 mm × 4 mm Body, Very Very Thin Quad
(CP-20-8)
Dimensions shown in millimeters
4.25
4.20
4.15
6.60
6.50
6.40
11
20
4.50
4.40
4.30
TOP
VIEW
1
3.05
3.00
2.95
EXPOSED
PAD
(Pins Up)
6.40
BSC
10
BOTTOM VIEW
1.05
1.00
0.80
1.20 MAX
0.15
0.05
0.30
0.19
SEATING
PLANE
COPLANARITY
0.10
FOR PROPER CONNECTION OF
THE EXPOSED PAD, REFER TO
THE PIN CONFIGURATION AND
FUNCTION DESCRIPTIONS
SECTION OF THIS DATA SHEET.
8°
0°
0.20
0.09
0.75
0.60
0.45
COMPLIANT TO JEDEC STANDARDS MO-153-ACT
05-08-2006-A
0.65 BSC
Figure 53. 20-Lead Thin Shrink Small Outline With Exposed Pad [TSSOP_EP]
(RE-20-1)
Dimensions shown in millimeters
ORDERING GUIDE
Model1
ADP5071ACPZ
ADP5071ACPZ-R7
ADP5071AREZ
ADP5071AREZ-R7
ADP5071CP-EVALZ
ADP5071RE-EVALZ
1
Temperature Range
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
Package Description
20-Lead Lead Frame Chip Scale Package [LFCSP_WQ]
20-Lead Lead Frame Chip Scale Package [LFCSP_WQ]
20-Lead Thin Shrink Small Outline With Exposed Pad [TSSOP_EP]
20-Lead Thin Shrink Small Outline With Exposed Pad [TSSOP_EP]
Evaluation Board for the LFCSP_WQ
Evaluation Board for the TSSOP_EP
Z = RoHS Compliant Part.
©2015 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D12069-0-6/15(A)
Rev. A | Page 27 of 27
Package Option
CP-20-8
CP-20-8
RE-20-1
RE-20-1