3

Pin Descriptions

PIN NO.

DESIGNATOR

FUNCTION

DESCRIPTION

1

ISET

Current Set

Connect to the low side of the current sense resistor through the current limiting set resistor.

This pin functions as the current regulation level voltage programming pin.

2

ISEN

Current Sense

Connect to the more positive end of sense resistor to measure the voltage drop across this

resistor.

3

GATE

External FET Gate

Drive Pin

Connect to the gate of the external N-Channel MOSFET. A capacitor from this node to

ground sets the turn-on ramp. At turn-on this capacitor will be charged to VB +5V by a 10

µA

current source.

4

VB_Ret

VB Chip Return

Bulk voltage ground

5

VA_Ret

VA Chip Return

Auxiliary voltage ground

6

VA_IN

VA Bias, Controlled

Supply Input,

Undervoltage Lock-Out

VA_IN provides the chip with +5V bias voltage. At VA < 2.5V, VA control functionality is

disabled, FAULT latch is cleared and floating and VA_OUT is held low.

7

VA_ENn

VA enable / disable

Connected to VA_Ret through the IB connector, VA is asserted on module when VA_ENn

is low. Cycle to reset after latch-off. POR also resets latch.

8NC

NC

9

VA_OUT

Controlled Supply

Output

Upon an OC condition VA_OUT is current limited to 1A. Current limit response time is within

200

µs. VA_Out will remain in current limit for ~10mS before being latched off.

10

VA_ FLTn

Over Current Fault

Indicator

Over current fault indicator. VA_FLTn floats and is disabled until VA >2.5V. This output is

pulled low after the OC time-out period has expired and stays latched until module is

removed.

11

VB_IN

VB / Chip Supply

+12V Chip Supply.

12

CTIM

VB Current Regulation

Period

Connect a capacitor from this pin to ground. This capacitor determines the time delay

between an overcurrent event and chip output shutdown (current limit time-out). The

duration of current limit time-out (in seconds) = 93k

13

DC-DC

ENABLE

VB_In Power Good

and DC-DC Enable

Signal

Indicates that the VB voltage on ISEN pin is within specification and enables the DC-DC

converter. DC-DC ENABLE is driven by an open drain N-Channel MOSFET and is pulled

14

VB_ON

VB Sequencer Enable

Control Signal

VB_ON is used to control and reset the VB supply to IB module. VB is asserted on, when

VB_ON pin is driven high or is open. After a latch-off VB is reset by a low level signal applied

to this pin. This input has 20

µA pull-up capability.

ISL6160