2-285

Functional Pin Descriptions

VCC (Pin 28)

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. The voltage at this pin is monitored for

Power-On Reset (POR) purposes.

GND (Pin 17)

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

respect to this pin.

PGND (Pin 24)

This is the power ground connection. Tie the synchronous

PWM converter’s lower MOSFET source to this pin.

VAUX (Pin 16)

The +3.3V input voltage at this pin is monitored for power-on

reset (POR) purposes. Connected to +5V input, this pin

provides boost current for the two linear regulator output

drives in the event bipolar NPN transistors (instead of

N-channel MOSFETs) are employed as pass elements.

PWM CONTROLLERS GATE DRIVERS

UGATE1,2 Source

-

1

-

A

UGATE1,2 Sink

-

1.7

3.5

Ω

LGATE Source

-

1

-

A

LGATE Sink

-

1.4

3.0

Ω

PROTECTION

VSEN1 Over-Voltage (VSEN1/DACOUT)

VSEN1 Rising

-

115

120

%

FAULT Sourcing Current

-

8.5

-

mA

OCSET1,2 Current Source

170

200

230

µA

Soft-Start Current

-28-

µA

POWER GOOD

VSEN1 Upper Threshold

(VSEN1/DACOUT)

VSEN1 Rising

108

-

110

%

VSEN1 Under-Voltage

(VSEN1/DACOUT)

VSEN1 Rising

92

-

94

%

VSEN1 Hysteresis (VSEN1/DACOUT)

Upper/Lower Threshold

-

2

-

%

PGOOD Voltage Low

-

-

0.8

V

Electrical Specifications

Recommended Operating Conditions, Unless Otherwise Noted. Refer to Figures 1, 2 and 3 (Continued)

PARAMETER

SYMBOL

TEST CONDITIONS

MIN

TYP

MAX

UNITS

Typical Performance Curves

FIGURE 2. BIAS SUPPLY CURRENT vs FREQUENCY

10

100

1000

SWITCHING FREQUENCY (kHz)

10

100

1000

TO +12V

100

200

300

400

500

600

700

800

900

1000

SWITCHING FREQUENCY (kHz)

140

120

100

80

60

40

20

0

C = 660pF

C = 1500pF

C = 3600pF

C = 4800pF

HIP6020