RC5054A

PRODUCT SPECIFICATION

2

age-mode control with fast transient response. It includes a

200KHz free-running triangle-wave oscillator that is adjust-

able from 50KHz to 1MHz. The error amplifier features a

15MHz gain-bandwidth product and 6V/

µs slew rate which

enables high converter bandwidth for fast transient perfor-

mance. The resulting PWM duty ratio ranges from 0% to

100%.

The RC5054A monitors the output voltage with a window

comparator that tracks the DAC output and issues a Power

Good signal when the output is within

±10%. The RC5054A

protects against over-current conditions by inhibiting PWM

operation. Built-in over-voltage protection triggers an exter-

nal SCR to crowbar the input supply. The RC5054A moni-

which eliminates the need for a current sensing resistor.

Pin Assignments

VSEN

OCSET

SS

VID0

VID1

VID2

VID4

VID3

COMP

FB

RT

VCC

LGATE

PGND

OVP

BOOT

UGATE

PHASE

PGOOD

GND

RC5054

(SOIC)

TOP VIEW

11

12

13

14

15

16

17

18

20

19

10

9

8

7

6

5

4

3

2

1

Pin Definitions

Pin Number Pin Names

Pin Function Description

1

VSEN

This pin is connected to the converter’s output voltage. The PGOOD and OVP

comparator circuits use this signal to report output voltage status and for overvoltage

protection.

2

OCSET

following equation:

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

3

SS

Connect a capacitor from this pin to ground. This capacitor, along with an internal

10

µA current source, sets the soft-start interval of the converter.

4-8

VID0-VID4

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 converter

output voltage. It also sets the PGOOD and OVP thresholds. Table 1 specifies

DACOUT for the 32 combinations of DAC inputs.

9

COMP

COMP and FB are the available external pins of the error amplifier. The FB pin is the

inverting input of the error amplifier and the COMP pin is the error amplifier output.

These pins are used to compensate the voltage-control feedback loop of the

converter.

10

FB

11

GND

Signal ground for the IC. All voltage levels are measured with respect to this pin.

12

PGOOD

PGOOD is an open collector output used to indicate the status of the converter

output voltage. This pin is pulled low when the converter output is not within

±10% of

the DACOUT reference voltage.

13

PHASE

Connect the PHASE pin to the upper MOSFET source. This pin is used to monitor

the voltage drop across the MOSFET for over-current protection. This pin also

provides the return path for the upper gate drive.

14

UGATE

Connect UGATE to the upper MOSFET gate. This pin provides the gate drive for the

upper MOSFET.

15

BOOT

This pin provides bias voltage to the upper MOSFET driver. A bootstrap circuit may

be used to create a BOOT voltage suitable to drive a standard N-Channel MOSFET.

16

PGND

This is the power ground connection. Tie the lower MOSFET source to this pin.

I

PEAK

I

OCS

R

OCSET

•

R

DS ON

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