NCP1855

http://onsemi.com

3

Table 1. PIN FUNCTION DESCRIPTION

Pin

Name

Type

Description

A1

IN

POWER

Battery Charger Input. These two pins must be decoupled by at least 1

mF capacitor and

connected together.

A2

IN

POWER

A3

SPM

DIGITAL INPUT

System Power Monitor input.

A4

SDA

DIGITAL

BIDIRECTIONAL

A5

SCL

DIGITAL INPUT

B1

CAP

POWER

CAP pin is the intermediate power supply input for all internal circuitry. Bypass with at

least 4.7

mF capacitor. Must be tied together.

B2

CAP

POWER

B3

OTG

DIGITAL INPUT

Enables OTG boost mode.

OTG = 0, the boost is powered OFF

OTG = 1 turns boost converter ON

B4

ILIM2

DIGITAL INPUT

B5

FLAG

OPEN DRAIN

OUTPUT

Charging state active low. This is an open drain pin that can either drive a status LED or

connect to interrupt pin of the system.

C1

SW

ANALOG OUTPUT

Connection from power MOSFET to the Inductor.

These pins must be connected together.

C2

SW

ANALOG OUTPUT

C3

AGND

ANALOG GROUND

Analog ground / reference. This pin should be connected to the ground plane and must

be connected together.

C4

ILIM1

DIGITAL INPUT

C5

FTRY

DIGITAL INPUT

Factory mode pin. Refer to section “Factory mode and no battery operation”. Internally

pulled up to CORE pin.

D1

PGND

POWER GND

Power ground. These pins should be connected to the ground plane and must be

connected together.

D2

PGND

POWER GND

D3

SENSP

ANALOG INPUT

Current sense input. This pin is the positive current sense input. It should be connected to

D4

SENSN

ANALOG INPUT

Current sense input. This pin is the negative current sense input. It should be connected

age regulation loop when the FET is present and open.

D5

FET

ANALOG OUTPUT

Battery FET driver output. When not used, this pin must be directly tied to ground.

E1

CBOOT

ANALOG IN/OUT

Floating Bootstrap connection. A 10 nF capacitor must be connected between CBOOT

and SW.

E2

TRANS

ANALOG OUTPUT

Output supply to USB transceiver. This pin can source a maximum of 50 mA to the

external USB PHY or any other IC that needs +5 V USB. This pin is Overvoltage

protected and will never be higher than 5.5 V. This pin should be bypassed by a 100 nF

ceramic capacitor.

E3

CORE

ANALOG OUTPUT

5 V reference voltage of the IC. This pin should be bypassed by a 2.2

mF capacitor.

No load must be connected to this pin.

E4

WEAK

ANALOG OUTPUT

Weak battery charging current source input.

E5

BAT

ANALOG INPUT

Battery connection