ANALOG DEVICES ADP1875 Service Manual

Synchronous Buck Controller with Constant

V

V

V

FEATURES

Power input voltage range: 2.95 V to 20 V
On-board bias regulator
Minimum output voltage: 0.6 V

0.6 V reference voltage with ±1.0% accuracy
Supports all N-channel MOSFET power stages
Available in 300 kHz, 600 kHz, and 1.0 MHz options
No current-sense resistor required
Power saving mode (PSM) for light loads (ADP1875 only)
Resistor programmable current limit
Power good with internal pull-up resistor
Externally programmable soft start
Thermal overload protection
Short-circuit protection
Standalone precision enable input
Integrated bootstrap diode for high-side drive
Starts into a precharged output
Available in a 16-lead QSOP package

APPLICATIONS

Telecom and networking systems
Mid- to high-end servers
Set-top boxes
DSP core power supplies

GENERAL DESCRIPTION

The ADP1874/ADP1875 are versatile current mode, synchronous
step-down controllers. They provide superior transient response,
optimal stability, and current-limit protection by using a constant
on-time, pseudo fixed frequency with a programmable current
limit, current control scheme. In addition, these devices offer
optimum performance at low duty cycles by using a valley, current
mode control architecture. This allows the ADP1874/ADP1875
to drive all N-channel power stages to regulate output voltages
to as low as 0.6 V.

The ADP1875 is the power saving mode (PSM) version of
the device and is capable of pulse skipping to maintain output
regulation while achieving improved system efficiency at light
loads (see the ADP1875 Power Saving Mode (PSM) section for
more information).

Available in three frequency options (300 kHz, 600 kHz, and

1.0 MHz, plus the PSM option), the ADP1874/ADP1875 are well
suited for a wide range of applications that require a single-input
power supply range from 2.95 V to 20 V. Low voltage biasing is
supplied via a 5 V internal low dropout regulator (LDO).

On-Time and Valley Current Mode

ADP1874/ADP1875

TYPICAL APPLICATIONS CIRCUIT

= 2.95V TO 20

IN

C

C

C

C2

R

C

10k

REG

R

TOP

V

OUT

R

BOT

C

VREG2

C

VREG

R

RES

100

VIN = 5V (PSM)

95
90
85
80
75
70
65
60

VIN = 13V (PSM)

55

EFFICIENCY (%)

50
45

VIN = 16.5V (PSM)

40
35
30
25

10 100 1k 10k 100k

Figure 2. ADP1874/ADP1875 Efficiency vs. Load Current (V

In addition, soft start programmability is included to limit input in­rush current from the input supply during startup and to
provide reverse current protection during precharged output
conditions. The low-side current sense, current gain scheme, and
integration of a boost diode, along with the PSM/forced pulse­width modulation (PWM) option, reduce the external part count
and improve efficiency.

The ADP1874/ADP1875 operate over the −40°C to +125°C
junction temperature range and are available in a 16-lead QSOP
package.

VIN

ADP1874/

ADP1875

COMP BST

EN

DRVH

FB

GND

VREG

VREG_IN
RES

SW

DRVL

PGOOD

TRACK

PGND

SS

C

IN

C

Q1

BST

C

Q2

R

PGD

V

EXT

C

SS

R

TRK2

R

TRK1

Figure 1. Typical Applications Circuit

VIN = 16.5V

VIN = 13V

TA = 25°C
V

= 1.8V

OUT

f

= 300kHz

SW

WÜRTH INDUCTOR:
744325120, L = 1.2µH, DCR = 1.8m

INFINEON FETs:
BSC042N03MS G (UPPER/LOWER)

LOAD CURRENT (mA)

L

OUT

LOAD

V

MASTER

= 1.8 V, 300 kHz)

OUT

V

OUT

09347-001

09347-102

Rev. 0

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rights of third parties that may result from its use. Specifications subject to change without notice. No
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Tel: [phone] www.analog.com
Fax: [phone] ©2011 Analog Devices, Inc. All rights reserved.

ADP1874/ADP1875

TABLE OF CONTENTS

Features.............................................................................................. 1

Applications....................................................................................... 1

General Description ......................................................................... 1

Typical Applications Circuit............................................................ 1

Revision History ............................................................................... 2

Specifications..................................................................................... 3

Absolute Maximum Ratings............................................................ 6

Thermal Resistance ...................................................................... 6

Boundary Condition .................................................................... 6

ESD Caution.................................................................................. 6

Pin Configuration and Function Descriptions............................. 7

Typical Performance Characteristics ............................................. 8

ADP1874/ADP1875 Block Digram.............................................. 18

Theory of Operation ...................................................................... 19

Startup.......................................................................................... 19

Soft Start ...................................................................................... 19

Precision Enable Circuitry ........................................................19

Undervoltage Lockout ............................................................... 19

On-Board Low Dropout Regulator.......................................... 20

Thermal Shutdown..................................................................... 20

Programming Resistor (RES) Detect Circuit.......................... 20

Valley Current-Limit Setting .................................................... 20

Hiccup Mode During Short Circuit......................................... 22

Synchronous Rectifier................................................................ 22

ADP1875 Power Saving Mode (PSM) ..................................... 22

Timer Operation ........................................................................ 23

Pseudo-Fixed Frequency........................................................... 24

Power Good Monitoring ........................................................... 24

Voltage Tracking......................................................................... 25

Applications Information.............................................................. 27

Feedback Resistor Divider ........................................................ 27

Inductor Selection...................................................................... 27

Output Ripple Voltage (VRR) .................................................. 27

Output Capacitor Selection....................................................... 27

Compensation Network ............................................................ 28

Efficiency Consideration........................................................... 29

Input Capacitor Selection.......................................................... 30

Thermal Considerations............................................................ 31

Design Example.......................................................................... 32

External Component Recommendations.................................... 34

Layout Considerations................................................................... 36

IC Section (Left Side of Evaluation Board)............................. 38

Power Section ............................................................................. 38

Differential Sensing.................................................................... 39

Typical Application Circuits ......................................................... 40

12 A, 300 kHz High Current Application Circuit.................. 40

5.5 V Input, 600 kHz Application Circuit ............................... 40

300 kHz High Current Application Circuit............................ 41

Outline Dimensions....................................................................... 42

Ordering Guide .......................................................................... 42

REVISION HISTORY

2/11—Revision 0: Initial Version

Rev. 0 | Page 2 of 44

ADP1874/ADP1875

SPECIFICATIONS

All limits at temperature extremes are guaranteed via correlation using standard statistical quality control (SQC). VREG = 5 V,
BST − SW = VREG − V

RECT_DROP

unless otherwise specified.

Table 1.

Parameter Symbol Test Conditions/Comments Min Typ Max Unit

POWER SUPPLY CHARACTERISTICS

High Input Voltage Range VIN C
ADP1874ARQZ-0.3/ADP1875ARQZ-0.3 (300 kHz) 2.95 12 20 V
ADP1874ARQZ-0.6/ADP1875ARQZ-0.6 (600 kHz) 2.95 12 20 V
ADP1874ARQZ-1.0/ADP1875ARQZ-1.0 (1.0 MHz) 3.25 12 20 V
Quiescent Current I
Shutdown Current I
Undervoltage Lockout UVLO Rising VIN (see Figure 35 for temperature variation) 2.65 V
UVLO Hysteresis Falling VIN from operational state 190 mV

INTERNAL REGULATOR

CHARACTERISTICS

VREG Operational Output Voltage VREG C
ADP1874ARQZ-0.3/ADP1875ARQZ-0.3 (300 kHz) 2.75 5 5.5 V
ADP1874ARQZ-0.6/ADP1875ARQZ-0.6 (600 kHz) 2.75 5 5.5 V
ADP1874ARQZ-1.0/ADP1875ARQZ-1.0 (1.0 MHz) 3.05 5 5.5 V
VREG Output in Regulation VIN = 7 V, 100 mA 4.82 4.981 5.16 V
V
Load Regulation 0 mA to 100 mA, VIN = 7 V 32 mV
0 mA to 100 mA, VIN = 20 V 34 mV
Line Regulation VIN = 7 V to 20 V, 20 mA 2.5 mV
V
VIN to VREG Dropout Voltage 100 mA out of VREG, VIN ≤ 5 V 300 415 mV
Short VREG to PGND VIN = 20 V 229 320 mA

SOFT START

Soft Start Period Calculation

ERROR AMPLIFER

FB Regulation Voltage VFB T
T
T
Transconductance Gm 320 496 670 μS
FB Input Leakage Current I

CURRENT-SENSE AMPLIFIER GAIN

Programming Resistor (RES)

Value from RES to PGND
RES = 22 kΩ ± 1% 5.5 6 6.5 V/V
RES = none 11 12 13 V/V
RES = 100 kΩ ± 1% 22 24 26 V/V

SWITCHING FREQUENCY

ADP1874ARQZ-0.3/

ADP1875ARQZ-0.3 (300 kHz)

On-Time VIN = 5 V, V

Minimum On-Time VIN = 20 V 145 190 ns

Minimum Off-Time 84% duty cycle (maximum) 340 400 ns

(see Figure 40 to Figure 42). VIN = 12 V. The specifications are valid for TJ = −40°C to +125°C,

= 22 μF(25 V rating) to PGND (at Pin 1)

VIN

+ I

Q_REG

REG,SD

FB = 1.5 V, no switching 1.1 mA

Q_BST

+ I

EN < 600 mV 140 225 μA

BST,SD

VREG and VREG_IN tied together and should not be
loaded externally because they are intended to only
bias internal circuitry

= 4.7 μF to PGND, 0.22 μF to GND, VIN = 2.95 V to 20 V

VREG

= 12 V, 100 mA 4.83 4.982 5.16 V

IN

= 7 V to 20 V, 100 mA 2 mV

IN

Connect external capacitor from SS pin to GND,

= 10 nF/ms

C

SS

= 25°C 600 mV

J

= −40°C to +85°C 596 600 604 mV

J

= −40°C to +125°C 594.2 600 605.8 mV

J

FB = 0.6 V, EN = VREG 1 50 nA

FB, LEAK

10 nF/ms

RES = 47 kΩ ± 1% 2.7 3 3.3 V/V

Typical values measured at 50% time points with
0 nF at DRVH and DRVL; maximum values are
guaranteed by bench evaluation

1

300 kHz

= 2 V, TJ = 25°C 1120 1200 1280 ns

OUT

Rev. 0 | Page 3 of 44

ADP1874/ADP1875

Parameter Symbol Test Conditions/Comments Min Typ Max Unit

ADP1874ARQZ-0.6/

ADP1875ARQZ-0.6 (600 kHz)
On-Time VIN = 5 V, V
Minimum On-Time VIN = 20 V, V
Minimum Off-Time 65% duty cycle (maximum) 340 400 ns

ADP1874ARQZ-1.0/

ADP1875ARQZ-1.0 (1.0 MHz)
On-Time VIN = 5 V, V
Minimum On-Time VIN = 20 V 52 85 ns
Minimum Off-Time 45% duty cycle (maximum) 340 400 ns

OUTPUT DRIVER CHARACTERISTICS

High-Side Driver

Output Source Resistance2 I
Output Sink Resistance2 I
Rise Time3 t
Fall Time3 t

Low-Side Driver

Output Source Resistance2 I
Output Sink Resistance2 I
Rise Time3 t
Fall Time3 t

Propagation Delays

DRVL Fall to DRVH Rise3 t

DRVH Fall to DRVL Rise3 t
SW Leakage Current I
Integrated Rectifier

Channel Impedance I

PRECISION ENABLE THRESHOLD

Logic High Level VIN = 2.9 V to 20 V, VREG = 2.75 V to 5.5 V 605 634 663 mV
Enable Hysteresis VIN = 2.9 V to 20 V, VREG = 2.75 V to 5.5 V 31 mV

COMP VOLTAGE

COMP Clamp Low Voltage V

COMP Clamp High Voltage V
COMP Zero Current Threshold V

THERMAL SHUTDOWN T

Thermal Shutdown Threshold Rising temperature 155 °C
Thermal Shutdown Hysteresis 15 °C

CURRENT LIMIT

Hiccup Current Limit Timing COMP = 2.4 V 6 ms

OVERVOLTAGE AND POWER GOOD

THRESHOLDS
FB Power Good Threshold FB
FB Power Good Hysteresis 30 mV
FB Overvoltage Threshold FBOV V
FB Overvoltage Hysteresis 30 mV
PGOOD Low Voltage During Sink V
PGOOD Leakage Current PGOOD = 5 V 1 400 nA

600 kHz

= 2 V, TJ = 25°C 500 540 580 ns

OUT

= 0.8 V 82 110 ns

OUT

1.0 MHz

= 2 V, TJ = 25°C 285 312 340 ns

OUT

= 1.5 A, 100 ns, positive pulse (0 V to 5 V) 2.25 3 Ω

SOURCE

= 1.5 A, 100 ns, negative pulse (5 V to 0 V) 0.70 1 Ω

SINK

BST − SW = 4.4 V, CIN = 4.3 nF (see Figure 59) 25 ns

r, DR VH

BST − SW = 4.4 V, CIN = 4.3 nF (see Figure 60) 11 ns

f, DRV H

= 1.5 A, 100 ns, positive pulse (0 V to 5 V) 1.6 2.2 Ω

SOURCE

= 1.5 A, 100 ns, negative pulse (5 V to 0 V) 0.7 1 Ω

SINK

VREG = 5.0 V, CIN = 4.3 nF (see Figure 60) 18 ns

r,DR VL

VREG = 5.0 V, CIN = 4.3 nF (see Figure 59) 16 ns

f,DRV L

BST − SW = 4.4 V (see Figure 59) 15.4 ns

tpdhDRVH

BST − SW = 4.4 V (see Figure 60) 18 ns

tpdhDRVL

BST = 25 V, SW = 20 V, VREG = 5 V 110 μA

SWLEAK

= 10 mA 22 Ω

SINK

COMP(LOW )

Tie EN pin to VREG to enable device

0.47 V

(2.75 V ≤ VREG ≤ 5.5 V)

(2.75 V ≤ VREG ≤ 5.5 V) 2.55 V

COMP(H IGH)

(2.75 V ≤ VREG ≤ 5.5 V) 1.15 V

COMP_ZC T

TMSD

PGOOD

PGD

PGOOD

VFB rising during system power-up 542 566 mV

rising during overvoltage event, I

FB

I

= 1 mA 143 200 mV

PGOOD

Rev. 0 | Page 4 of 44

= 1 mA 691 710 mV

PGOOD

ADP1874/ADP1875

Parameter Symbol Test Conditions/Comments Min Typ Max Unit

TRACKING

Track Input Voltage Range 0 5 V
FB-to-Tracking Offset Voltage 0.5 V < TRACK < 0.6 V, offset = VFB − V
Leakage Current V

1

The maximum specified values are with the closed loop measured at 10% to 90% time points (see Figure and Figure 60), C

MOSFETs being Infineon BSC042N03MS G.

2

Guaranteed by design.

3

Not automatic test equipment (ATE) tested.

= 5 V 1 50 nA

TRACK

63 mV

TRACK

59

= 4.3 nF, and the upper- and lower-side

GATE

Rev. 0 | Page 5 of 44

ADP1874/ADP1875

ABSOLUTE MAXIMUM RATINGS

Table 2.

Parameter Rating

VREG, VREG_IN, TRACK to PGND, GND −0.3 V to +6 V
VIN, EN, PGOOD to PGND −0.3 V to +28 V
FB, COMP, RES, SS to GND −0.3 V to (VREG + 0.3 V)
DRVL to PGND −0.3 V to (VREG + 0.3 V)
SW to PGND −2.0 V to +28 V
BST to SW −0.6 V to (VREG + 0.3 V)
BST to PGND −0.3 V to +28 V
DRVH to SW −0.3 V to VREG
PGND to GND ±0.3 V
PGOOD Input Current 35 mA
θJA (16-Lead QSOP)

4-Layer Board 104°C/W

Operating Junction Temperature Range −40°C to +125°C
Storage Temperature Range −65°C to +150°C
Soldering Conditions JEDEC J-STD-020
Maximum Soldering Lead Temperature

(10 sec)

Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.

Absolute maximum ratings apply individually only, not in
combination. Unless otherwise specified, all other voltages are
referenced to PGND.

300°C

THERMAL RESISTANCE

θJA is specified for the worst-case conditions, that is, a device
soldered in a circuit board for surface-mount packages.

Table 3. Thermal Resistance

Package Type θJA Unit

θJA (16-Lead QSOP)

4-Layer Board 104° °C/W

BOUNDARY CONDITION

In determining the values given in Ta b le 2 and Tabl e 3, natural
convection is used to transfer heat to a 4-layer evaluation board.

ESD CAUTION

Rev. 0 | Page 6 of 44

ADP1874/ADP1875

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

VIN

1

COMP

2

3

EN

ADP1874/

ADP1875

FB

4

GND

RES

VREG

VREG_IN

TOP VIEW

5

(Not to Scale)

6

7

8

Figure 3. Pin Configuration

Table 4. Pin Function Descriptions

Pin

No.

Mnemonic Description

1 VIN High-Side Input Voltage. Connect VIN to the drain of the upper-side MOSFET.

2 COMP

Output of the Error Amplifier. Connect the compensation network between this pin and AGND to achieve stability

(see the Compensation Network section).
3 EN Connect to VREG to Enable IC. When pulled down to AGND externally, disables the IC.
4 FB Noninverting Input of the Internal Error Amplifier. This is the node where the feedback resistor is connected.
5 GND

Analog Ground Reference Pin of the IC. All sensitive analog components should be connected to this ground plane

(see the Layout Considerations section).
6 RES Current Sense Gain Resistor (External). Connect a resistor between the RES pin and GND (Pin 5).
7 VREG

Internal Regulator Supply Bias Voltage for the ADP1874/ADP1875 Controller (Includes the Output Gate Drivers). A

bypass capacitor of 1 μF directly from this pin to PGND and a 0.1 μF across VREG and GND are recommended.
8 VREG_IN Input to the Internal LDO. Tie this pin directly to Pin 7 (VREG).
9 TRACK

Tracking Input. If the tracking function is not used, it is recommended to connect TRACK to VREG through a resistor

higher than 1 MΩ or simply connect TRACK between 0.7 V and 2 V to reduce the bias current going into the pin.
10 SS

Soft Start Input. Connect an external capacitor to GND to program the soft start period. Capacitance value of 10 nF for

every 1 ms of soft start delay.
11 PGOOD

Open-Drain Power Good Output. Sinks current when FB is out of regulation or during thermal shutdown. Connect a

3 kΩ resistor between PGOOD and VREG. Leave unconnected if not used.
12 DRVL

Drive Output for the External Lower-Side, N-Channel MOSFET. This pin also serves as the current-sense gain setting

pin (see Figure 69).
13 PGND Power GND. Ground for the lower-side gate driver and lower-side, N-channel MOSFET.
14 DRVH Drive Output for the External Upper-Side, N-Channel MOSFET.
15 SW Switch Node Connection.
16 BST

Bootstrap for the Upper-Side MOSFET Gate Drive Circuitry. An internal boot rectifier (diode) is connected between

VREG and BST. A capacitor from BST to SW is required. An external Schottky diode can also be connected between

VREG and BST for increased gate drive capability.

16

15

14

13

12

11

10

9

BST
SW

DRVH
PGND
DRVL
PGOOD

SS
TRACK

09347-003

Rev. 0 | Page 7 of 44

ADP1874/ADP1875

TYPICAL PERFORMANCE CHARACTERISTICS

100

95
90

VIN = 13V (PSM)

85
80
75
70
65
60
55
50
45
40

EFFICIENCY (%)

35

VIN = 16.5V (PSM)

30
25
20
15
10

5
0

10 100 1k 10k 100k

TA = 25°C
V

OUT

f

= 300kHz

SW

WÜRTH INDUCTOR:
744325072, L = 0.72µH, DCR = 1.3m

INFINEON FETs:
BSC042N03MS G (UPPER/LOWER)

LOAD CURRENT (mA)

Figure 4. Efficiency—300 kHz, V

VIN = 13V

= 0.8V

VIN = 16.5V

= 0.8 V

OUT

09347-104

100

95
90
85
80
75
70
65
60
55
50
45
40

EFFICIENCY (%)

35
30
25
20
15
10

5
0

10 100 1k 10k 100k

VIN = 13V (PSM)

VIN = 16.5V

(PSM)

Figure 7. Efficiency—600 kHz, V

VIN = 13V

VIN = 16.5V

TA = 25°C

= 0.8V

V

OUT

f

= 600kHz

SW

WÜRTH INDUCTOR:
744355147, L = 0.47µH, DCR = 0.67m

INFINEON FETs:
BSC042N03MS G (UPPER/LOWER)

LOAD CURRENT (mA)

= 0.8 V

OUT

09347-107

100

95

VIN = 5V (PSM)

90
85
80
75
70
65
60
55
50
45
40

EFFICIENCY (%)

35
30
25
20
15
10

5
0

VIN = 13V (PSM)

VIN = 16.5V (PSM)

10 100 1k 10k 100k

LOAD CURRENT (mA)

Figure 5. Efficiency—300 kHz, V

VIN = 16.5V

VIN = 13V

TA = 25°C

= 1.8V

V

OUT

f

= 300kHz

SW

WÜRTH INDUCTOR:
744325120, L = 1.2µH, DCR = 1.8m

INFINEON FETs:
BSC042N03MS G (UPPER/LOWER)

= 1.8 V

OUT

100

VIN = 16.5V (PSM)

95
90
85
80
75

VIN = 13V (PSM)

70
65
60
55
50
45
40

EFFICIENCY (%)

35
30
25
20
15
10

5
0

10 100 1k 10k 100k

Figure 6. Efficiency—300 kHz, V

VIN = 13V

VIN = 16.5V

TA = 25°C

= 7V

V

OUT

f

= 300kHz

SW

WÜRTH INDUCTOR:
7443551200, L = 2.0µH, DCR = 2.6m

INFINEON FETs:
BSC042N03MS G (UPPER/LOWER)

LOAD CURRENT (mA)

= 7 V

OUT

100

95
90
85

VIN = 13V (PSM)

80
75
70
65
60
55
50

VIN = 16.5V (PSM)

45
40

EFFICIENCY (%)

35
30
25
20
15
10

5
0

10 100 1k 10k 100k

09347-105

Figure 8. Efficiency—600 kHz, V

VIN = 13V

VIN = 16.5V

TA = 25°C

= 1.8V

V

OUT

f

= 600kHz

SW

WÜRTH INDUCTOR:
744325072, L = 0.72µH, DCR = 1.3m

INFINEON FETs:
BSC042N03MS G (UPPER/LOWER)

LOAD CURRENT (mA)

= 1.8 V

OUT

09347-108

100

95
90

VIN = 16.5V (PSM)

85
80
75
70
65
60
55
50
45
40

EFFICIENCY (%)

35
30
25
20
15
10

5
0

10 100 1k 10k 100k

09347-106

VIN = 13V (PSM)

VIN = 20V (PSM)

VIN = 20V

TA = 25°C
V

OUT

f

= 600kHz

SW

WÜRTH INDUCTOR:
744318180, L = 1.4µH, DCR = 3.2m

INFINEON FETs:
BSC042N03MS G (UPPER/LOWER)

LOAD CURRENT (mA)

Figure 9. Efficiency—600 kHz, V

VIN = 16.5V

= 5V

OUT

= 5 V

09347-109

Rev. 0 | Page 8 of 44

ADP1874/ADP1875

100

95
90
85
80
75
70

VIN = 13V (PSM)

65
60
55
50
45
40

EFFICIENCY (%)

35
30

VIN = 16.5V (PSM)

25
20
15
10

5
0

10 100 1k 10k 100k

Figure 10. Efficiency—1.0 MHz, V

VIN = 13V

VIN = 16.5V

TA = 25°C

= 0.8V

V

OUT

f

= 1.0MHz

SW

WÜRTH INDUCTOR:
744303012, L = 0.12µH, DCR = 0.33m

INFINEON FETs:
BSC042N03MS G (UPPER/LOWER)

LOAD CURRENT (mA)

= 0.8 V

OUT

09347-110

0.807

0.806

0.805

0.804

0.803

0.802

0.801

0.800

0.799

0.798

0.797

OUTPUT VOLTAGE (V)

0.796

0.795
VIN = 13V

0.794

0.793

0.792

+125°C
+25°C
–40°C

0 2000 4000 6000 8000 10,000

VIN = 16.5V

+125°C
+25°C
–40°C

LOAD CURRENT (mA)

Figure 13. Output Voltage Accuracy—300 kHz, V

OUT

= 0.8 V

09347-013

100

95
90
85
80

VIN = 13V (PSM)

75
70
65
60
55
50
45
40

VIN = 16.5V (PSM)

EFFICIENCY (%)

35
30
25
20
15
10

5
0

10 100 1k 10k 100k

Figure 11. Efficiency—1.0 MHz, V

VIN = 13V

VIN = 16.5V

TA = 25°C

= 1.8V

V

OUT

f

= 1.0MHz

SW

WÜRTH INDUCTOR:
744303022, L = 0.22µH, DCR = 0.33m

INFINEON FETs:
BSC042N03MS G (UPPER/LOWER)

LOAD CURRENT (mA)

= 1.8 V

OUT

100

95
90
85

VIN = 13V (PSM)

80
75
70
65
60
55

VIN = 16.5V (PSM)

50
45
40

EFFICIENCY (%)

35
30
25
20
15
10

5
0

10 100 1k 10k 100k

TA = 25°C
V

OUT

f

SW

WÜRTH INDUCTOR:
744355090, L = 0.9µH, DCR = 1.6m

INFINEON FETs:
BSC042N03MS G (UPPER/LOWER)

LOAD CURRENT (mA)

Figure 12. Efficiency—1.0 MHz, V

VIN = 16.5V

= 5V

= 1.0MHz

VIN = 13V

= 5 V

OUT

1.821

1.816

1.811

1.806

1.801

OUTPUT VOLTAGE (V)

1.796

1.791

1.786

0 1500 3000 4500 6000 7500 9000 10,500 12,000 13,500 15,000

09347-111

VIN = 5.5V

+125°C
+25°C
–40°C

Figure 14. Output Voltage Accuracy—300 kHz, V

VIN = 13V

+125°C
+25°C
–40°C

LOAD CURRENT (mA)

VIN = 16.5V

+125°C
+25°C
–40°C

OUT

= 1.8 V

09347-014

7.100

7.095

7.090

7.085

7.080

7.075

7.070

7.065

7.060

7.055

7.050

7.045

7.040

7.035

7.030

OUTPUT VOLTAGE (V)

7.025

7.020

7.015

7.010

7.005

7.000

09347-112

Figure 15. Output Voltage Accuracy—300 kHz, V

+125°C
+25°C
–40°C

0 1000 2000 3000 4000 5000 6000 7000 8000 9000

VIN = 13V
VIN = 16.5V

LOAD CURRENT (mA)

OUT

= 7 V

09347-015

Rev. 0 | Page 9 of 44

ADP1874/ADP1875

0.808

0.806

0.804

0.802

0.800

0.798

FREQUENCY (kHz)

0.796

0.794

0.792

+125°C
+25°C
–40°C

0 1000 2000 3000 4000 5000 6000 7000 8000 10,0009000

VIN = 13V
VIN = 16.5V

LOAD CURRENT (mA)

Figure 16. Output Voltage Accuracy—600 kHz, V

OUT

= 0.8 V

09347-115

0.807

0.805

0.803

0.801

0.799

0.797

0.795

0.793

OUTPUT VOLTAGE (V)

0.791

0.789

0.787
0 2000 4000 6000 8000 10,000

VIN = 13V

LOAD CURRENT (mA)

+125°C
+25°C
–40°C

VIN = 16.5V

+125°C
+25°C
–40°C

Figure 19. Output Voltage Accuracy—1.0 MHz, V

OUT

= 0.8 V

09347-118

1.818

1.816

1.814

1.812

1.810

1.808

1.806

1.804

1.802

1.800

1.798

1.796

1.794

1.792

1.790

1.788

1.786

1.784

OUTPUT VOLTAGE (V)

1.782

1.780

1.778

1.776

1.774

1.772

1.770
0 12,00010,500900075006000450030001500

VIN = 13V

LOAD CURRENT (mA)

+125°C
+25°C
–40°C

VIN = 16.5V

+125°C
+25°C
–40°C

Figure 17. Output Voltage Accuracy—600 kHz, V

5.030

5.025

5.020

5.015

5.010

5.005

5.000

4.995

4.990

OUTPUT VOLTAGE (V)

4.985

4.980

4.975

4.970

+125°C
+25°C
–40°C

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10,000

VIN = 13V
VIN = 16.5V
VIN = 20V

LOAD CURRENT (mA)

Figure 18. Output Voltage Accuracy—600 kHz, V

OUT

OUT

= 1.8 V

= 5 V

1.820

1.815

1.810

1.805

1.800

OUTPUT VOLTAGE (V)

1.795

1.790

0

09347-016

VIN = 13V

LOAD CURRENT (mA)

Figure 20. Output Voltage Accuracy—1.0 MHz, V

+125°C
+25°C
–40°C

VIN = 16.5V

+125°C
+25°C
–40°C

OUT

= 1.8 V

10,0000 1000 2000 3000 4000 5000 6000 7000 8000 9000

09347-019

5.04

5.03

5.02

5.01

5.00

4.99

4.98

4.97

4.96

4.95

OUTPUT VOLTAGE (V)

4.94

4.93

4.92

4.91

4.90

09347-017

Figure 21. Output Voltage Accuracy—1.0 MHz, V

VIN = 13V

LOAD CURRENT (mA)

+125°C
+25°C
–40°C

VIN = 16.5V

+125°C
+25°C
–40°C

7200640056004800400024001600 32000 960088008000800

OUT

=5 V

09347-020

Rev. 0 | Page 10 of 44

ADP1874/ADP1875

601.0

600.5

600.0

599.5

599.0

598.5

FEEDBACK VOLTAGE (V)

598.0

597.5

597.0
–40.0 –7.5 25.0 57.5 90.0 122.5

VREG = 5V, V

VREG = 5V, VIN = 13V

= 20V

IN

TEMPERATURE (° C)

Figure 22. Feedback Voltage vs. Temperature

09347-121

900

880

860

840

820

800

780

760

SWITCHING FREQUENCY (kHz)

740

720

700

13.0 13.5 14. 0 14.5 15. 0 15.5 16.0 16.5

+125°C
+25°C
–40°C

VIN (V)

Figure 25. Switching Frequency vs. High Input Voltage, 1.0 MHz,

Range = 13 V to 16.5 V

V

IN

09347-124

325

315

305

295

285

275

SWITCHING FREQUENCY (kHz)

265

255

10.8 11. 0 11.2 11.4 11.6 11.8 12.0 12.2 12.4 12.6 12.8 13.0 13.2

+125°C
+25°C
–40°C

VIN (V)

NO LOAD

09347-022

Figure 23. Switching Frequency vs. High Input Voltage, 300 kHz, ±10% of 12 V

650

600

550

500

SWITCHING FREQUENCY (kHz)

450

400

13.0 13.4 13.8 14.2 14.6 15.0 15.4 15.8 16. 2 16.5

Figure 24. Switching Frequency vs. High Input Voltage, 600 kHz, V

+125°C
+25°C
–40°C

Range = 13 V to 16.5 V

V

IN

VIN (V)

NO LOAD

= 1.8 V,

OUT

09347-123

280

265

250

235

220

FREQUENCY (kHz)

205

190

VIN = 13V
VIN = 20V
VIN = 16.5V

0 10,0008000600040002000

+125°C
+25°C
–40°C

LOAD CURRENT (mA)

Figure 26. Frequency vs. Load Current, 300 kHz, V

330

320

310

300

290

280

270

FREQUENCY (kHz)

260

250

240

0 15,00012,000 13,50010,500900075006000450030001500

VIN = 20V
VIN = 13V
VIN = 16.5V

+125°C
+25°C
–40°C

LOAD CURRENT (mA)

Figure 27. Frequency vs. Load Current, 300 kHz, V

OUT

OUT

= 0.8 V

= 1.8 V

09347-025

09347-026

Rev. 0 | Page 11 of 44

ADP1874/ADP1875

338

334

330

326

322

318

314

FREQUENCY (kHz)

310

306

302

298

0 6400 7200 8000 8800560048004000320024001600800

VIN = 13V
VIN = 16.5V

+125°C
+25°C
–40°C

LOAD CURRENT (mA)

Figure 28. Frequency vs. Load Current, 300 kHz, V

OUT

= 7 V

09347-027

740
733
726
719
712
705
698
691
684
677
670
663

FREQUENCY (kHz)

656
649
642
635
628
621

0 96008800800072006400560048004000320024001600800

VIN = 13V
VIN = 16.5V

+125°C
+25°C
–40°C

LOAD CURRENT (mA)

Figure 31. Frequency vs. Load Current, 600 kHz, V

OUT

= 5 V

09347-030

540

510

480

450

420

390

FREQUENCY (kHz)

360

330

300

VIN = 13V
VIN = 16.5V

0 12,0001200 2400 3600 4800 6000 7200 8400 9600 10,800

+125°C
+25°C
–40°C

LOAD CURRENT (mA)

Figure 29. Frequency vs. Load Current, 600 kHz, V

675

655

635

615

595

575

555

FREQUENCY (kHz)

535

515

495

VIN = 13V
VIN = 16.5V

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10,000

LOAD CURRENT (mA)

Figure 30. Frequency vs. Load Current, 600 kHz, V

OUT

OUT

= 0.8 V

+125°C
+25°C
–40°C

= 1.8 V

850

775

700

625

550

FREQUENCY (kHz)

475

400

09347-028

Figure 32. Frequency vs. Load Current, V

VIN = 13V
VIN = 16.5V

0 12,00010,0008000600040002000

+125°C
+25°C
–40°C

LOAD CURRENT (mA)

= 1.0 MHz, 0.8 V

OUT

09347-031

1225

1150

1075

1000

925

850

775

FREQUENCY (kHz)

700

625

550

09347-029

Figure 33. Frequency vs. Load Current, 1.0 MHz, V

VIN = 13V +125°C
VIN = 16.5V

0 12,0009600 10,8008400720060004800360024001200

+25°C
–40°C

LOAD CURRENT (mA)

= 1.8 V

OUT

09347-032

Rev. 0 | Page 12 of 44

ADP1874/ADP1875

1450

1400

1350

1300

1250

1200

1150

FREQUENCY (kHz)

1100

1050

1000

08000

Figure 34. Frequency vs. Load Current, 1.0 MHz, V

= 13V +125°C

V

IN

= 16.5V

V

IN

800 1600 2400 3200 4000 4800 5600 6400 7200

LOAD CURRENT (mA)

+25°C
–40°C

OUT

= 5 V

09347-033

82

80

78

76

74

72

70

68

MAXIMUM DUTY CYCLE (%)

66

64

62

5.5 6.7 7.9 9.1 10.3 11.5 12.7 13.9 15.1 16.3

+125°C
+25°C
–40°C

VIN (V)

Figure 37. Maximum Duty Cycle vs. High Voltage Input (V

09347-036

)

IN

2.658

2.657

2.656

2.655

2.654

2.653

UVLO (V)

2.652

2.651

2.650

2.649

–40 120100806040200–20

TEMPERATURE (°C)

Figure 35. UVLO vs. Temperature

95

90

85

80

75

70

65

MAXIMUM DUTY CYCLE (%)

60

55

300 400 500 600 700 800 900 1000

FREQUENCY (kHz)

Figure 36. Maximum Duty Cycle vs. Frequency

+125°C
+25°C
–40°C

680

630

580

530

480

430

380

330

MINUMUM OFF-TIME (ns)

280

230

180

–40 120100806040200–20

09347-034

VREG = 2.7V
VREG = 3.6V
VREG = 5.5V

TEMPERATURE (° C)

09347-037

Figure 38. Minimum Off-Time vs. Temperature

680

630

580

530

480

430

380

330

MINUMUM OFF-TIME (ns)

280

230

180

2.7 5.55.14.74.33.93.53.1

09347-035

VREG (V)

+125°C
+25°C
–40°C

09347-038

Figure 39. Minimum Off-Time vs. VREG (Low Input Voltage)

Rev. 0 | Page 13 of 44

ADP1874/ADP1875

800

720

640

560

480

400

320

RECTIFIER DROP (mV)

240

160

80

300 400 500 600 700 800 900 1000

VREG = 2.7V
VREG = 3.6V
VREG = 5.5V

+125°C
+25°C
–40°C

FREQUENCY (kHz)

Figure 40. Internal Rectifier Drop vs. Frequency

09347-039

80

72

64

56

48

40

32

24

BODY DIODE CONDUCTION TIME (ns)

16

8

2.73.13.53.94.34.75.15.5

300kHz +125°C
1MHz

VREG (V)

+25°C
–40°C

Figure 43. Lower-Side MOSFET Body Diode Conduction Time vs. VREG

09347-042

1280
1200
1120
1040

960
880
800
720
640
560
480

RECTIFIER DROP (mV)

400
320
240
160

80

2.73.13.53.94.34.75.15.5

VIN = 5.5V
VIN = 13V
VIN = 16.5V

1MHz
300kHz

VREG (V)

TA = 25°C

Figure 41. Internal Boost Rectifier Drop vs. VREG (Low Input Voltage)

Variation

Over V

IN

720

640

560

480

400

300kHz +125°C
1MHz

+25°C
–40°C

OUTPUT VOLTAGE

1

2

3

4

CH1 50mV

09347-040

CH3 10V

B

CH2 5A 

W

B

CH4 5V

W

INDUCTOR CURRENT

SW NODE

LOW SIDE

M400ns A CH2 3.90A

T 35.8%

09347-043

Figure 44. Power Saving Mode (PSM) Operational Waveform, 100 mA

OUTPUT VOLTAGE

1

INDUCTOR CURRENT

2

320

RECTIFIER DROP (mV)

240

160

80

2.73.13.53.94.34.75.15.5
VREG (V)

Figure 42. Internal Boost Rectifier Drop vs. VREG

09347-041

Rev. 0 | Page 14 of 44

3

4

CH1 50mV
CH3 10V

B

CH2 5A 

W

B

CH4 5V

W

M4.0µs A CH2 3.90A

T 35.8%

Figure 45. PSM Waveform at Light Load, 500 mA

SW NODE

LOW SIDE

09347-044