Preliminary Technical Data

ADP1051

Rev. PrA | Page 9 of 17

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

Figure 3. Pin Configuration

Table 4. Pin Function Descriptions

Pin No.

Mnemonic

Description

1

VS-

Inverting Voltage Sense Input. This is the connection for the ground line of the power rail. There should be a

low ohmic connection to AGND. It is recommended that the resistor divider on this input have a tolerance

specification of 0.5% or better to allow for trimming.

2

VS+

Noninverting Voltage Sense Input. This signal is referred to VS−. It is recommended that the resistor divider on

this input have a tolerance specification of 0.5% or better to allow for trimming.

3

CS2-

Inverting Differential Current Sense Input. Nominal voltage at this pin should be 1.15 V for best operation.

When using high-side current sensing in a 12 V application, place a 5.62 kΩ resistor between the sense resistor

and this pin. When using low-side current sensing, place a 5 kΩ resistor between the sense resistor and this pin.

used to connect this circuit.

4

CS2+

Noninverting Differential Current Sense Input. Nominal voltage at this pin should be 1.15 V for best operation.

When using high-side current sensing in a 12 V application, place a 5.62 kΩ resistor between the sense resistor

and this pin. When using low-side current sensing, place a 5 kΩ resistor between the sense resistor and this pin.

used to connect this circuit.

5

VF

Three optional functions can be implemented with this pin: feed forward, primary side input voltage sensing

and input voltage lost detect. It is connected upstream of the output inductor through a resistor divider

network. The nominal voltage at this pin should be 1V. This signal is referred to AGND

6

CS1

Primary Side Current Sense Input. This pin is connected to the primary side current sensing ADC and to the fast

OCP comparator. This signal is referred to AGND. The resistors on this input must have a tolerance specification

of 0.5% or better to allow for trimming.

7

SR1

PWM logic output drive. This pin can be disabled when not in use. This signal is referred to AGND.

8

SR2

PWM logic output drive. This pin can be disabled when not in use. This signal is referred to AGND.

9

OUTA

PWM logic output drive. This pin can be disabled when not in use. This signal is referred to AGND.

10

OUTB

PWM logic output drive. This pin can be disabled when not in use. This signal is referred to AGND.

11

OUTC

PWM logic output drive. This pin can be disabled when not in use. This signal is referred to AGND. This pin can

also be programmed as a synchronization output.

12

OUTD

PWM logic output drive. This pin can be disabled when not in use. This signal is referred to AGND. This pin can

also be programmed as a synchronization output.

13

SYNI/FLGI

Synchronization signal input. It also used as an external signal input to generate a flag condition.

14

SCL

I2C/PMBus Serial Clock Input and Output (Open Drain). This signal is referred to AGND.

15

SDA

I2C/PMBus Serial Data Input and Output (Open Drain). This signal is referred to AGND.

16

CTRL

PMBus CONTROL signal. It is recommended that a 1 nF capacitor be included from the CTRL pin to AGND for

noise debounce and decoupling. This signal is referred to AGND.

17

PG/ALT#

Power Good Output (Open Drain). This signal is referred to AGND. This pin is also used PMBus ALERT# signal.

18

VCORE

Output of 2.6 V regulator. Connect a minimum 330 nF decoupling capacitor from this pin to the AGND as close

as possible to the IC, minimizing the PCB trace length. It is recommended that the VCORE pin not be used as a

reference or to generate other logic levels using resistive dividers.

19

VDD

Positive Supply voltage 3.0 V to 3.6 V referred to AGND. Connect a 2.2 μF decoupling capacitor from this pin to

the AGND as close as possible to the IC, minimizing the PCB trace length.

ADP1051

1

2

VS-

VS+

CTRL

VF

CS1

3

4

5

7

8

9

10

11

24

23

22

21

20

18

17

16

15

14

PG/ALT#

SYNI/FLGI

SDA

SCL

VCORE

TOP VIEW

(Not to Scale)

6

12

13

19

CS2-

CS2+