2-201

Functional Pin Descriptions

VSEN1 (Pin 19)

This pin is connected to the PWM converter’s output voltage.

The PGOOD and OVP comparator circuits use this signal to

report output voltage status and for over voltage protection.

OCSET (Pin 20)

set the PWM converter over-current (OC) trip point

according to the following equation:

An over-current trip cycles the soft-start function. Sustaining

an over-current for 2 soft-start intervals shuts down the

controller.

SS (Pin 9)

Connect a capacitor from this pin to ground. This capacitor,

along with an internal 11

µA (typically) current source, sets

the soft-start interval of the converter.

Pulling this pin low with an open drain signal will shut down

the IC.

VID0, VID1, VID2, VID3, VID4 (Pins 6, 5, 4, 3 and 2)

VID0-4 are the input pins to the 5-bit DAC. The states of

these five pins program the internal voltage reference

(DACOUT). The level of DACOUT sets the core converter

output voltage. It also sets the core PGOOD and OVP

thresholds.

COMP and FB (Pins 17 and 18)

COMP and FB are the available external pins of the PWM

error amplifier. The FB pin is the inverting input of the error

amplifier. Similarly, the COMP pin is the error amplifier

output. These pins are used to compensate the voltage-

control feedback loop of the PWM converter.

GND (Pin 14)

Signal ground for the IC. All voltage levels are measured with

respect to this pin.

PGOOD (Pin 7)

PGOOD is an open collector output used to indicate the

status of the output voltages. This pin is pulled low when the

core output is not within

±10% of the DACOUT reference

voltage and the other outputs are below their under-voltage

thresholds.

The PGOOD output is open for VID codes that inhibit

operation. See Table 1.

PHASE (Pin 23)

Connect the PHASE pin to the PWM converter’s upper

MOSFET source. This pin is used to monitor the voltage

drop across the upper MOSFET for over-current protection.

UGATE (Pin 24)

Connect UGATE pin to the PWM converter’s upper MOSFET

gate. This pin provides the gate drive for the upper MOSFET.

PGND (Pin 21)

This is the power ground connection. Tie the PWM

converter’s lower MOSFET source to this pin.

LGATE (Pin 22)

Connect LGATE to the PWM converter’s lower MOSFET

gate. This pin provides the gate drive for the lower MOSFET.

VCC (Pin 1)

Provide a 12V bias supply for the IC to this pin. This pin also

provides the gate bias charge for all the MOSFETs

controlled by the IC.

RT (Pin 10)

This pin provides oscillator switching frequency adjustment.

200kHz switching frequency is increased according to the

following equation:

to VCC reduces the switching frequency according to the

following equation:

FAULT (Pin 8)

This pin is low during normal operation, but it is pulled to VCC

in the event of an over-voltage or over-current condition.

GATE3 (Pin 15)

Connect this pin to the gate of an external MOSFET. This pin

provides the drive for the linear controller’s pass transistor.

VSEN3 (Pin 16)

regulated to 1.5V.

VOUT2 (Pin 13)

Output of the linear regulator. Supplies current up to 230mA

(typically).

VSEN2 (Pin 11)

voltage at this pin is regulated to 2.5V.

I

PEAK

I

OCSET

R

OCSET

×

r

DS ON

()

---------------------------------------------------------

=

Fs

200kHz

510

×

6

R

()

---------------------

+

≈

Fs

200kHz

410

7

×

R

()

---------------------

–

≈

HIP6016