DS2770

4 of 27

DETAILED PIN DESCRIPTION Table 1

PIN

SYMBOL

DESCRIPTION

1

UV

Battery Undervoltage Detect Output:

This pin allows charge of the

battery at a reduced rate when the battery cell voltage is less than the low

2

CC

Charge Control Output:

Charge of the battery is controlled through this

3VCH

Charge Supply Input:

The charge source is connected to this pin and is

measured by the DS2770 to determine if a charge source is present.

4, 5, 6

SNS

Sense Resistor Connection:

Connect to the negative terminal of the

battery pack. In the internal sense resistor configuration, the sense resistor

is connected between VSS and SNS.

8IS2

Current-Sense Input:

This pin is internally connected to SNS through a

10k

W resistor. Connect a 0.1mF capacitor between IS2 and IS1 to

complete a lowpass filter.

9IS1

Current-Sense Input:

This pin is internally connected to VSS through a

10k

W resistor. Connect a 0.1mF capacitor between IS1 and IS2 to

complete a lowpass filter.

11, 12, 13

VSS

Device Ground:

Connect directly to the negative terminal of the battery

cell. For the external sense resistor configuration, connect the sense

resistor between VSS and SNS.

14

DQ

Data Input/Out:

1-Wire data line. Open-drain output driver. Connect this

pin to the DATA terminal of the battery pack. Pin has an internal pull-

down for sensing disconnection.

15

VIN

Voltage Sense Input:

The voltage on the battery cell is monitored via this

input pin.

16

VDD

Power Supply Input:

Input supply voltage for the DS2770 (2.7V to

5.5V)

7, 10

NC

Do not connect.