DEVICE INFORMATION

PIN CONNECTIONS

1

2

3

4

16

15

14

13

PVDD2

BOOT2

SW2

BP

PVDD1

BOOT1

SW1

GND

5

6

7

12

11

10

SEQ

ILIM2

FB2

EN1

EN2

FB1

Thermal Pad

(bottom side)

HTSSOP (PWP)

(Top View)

8

9

COMP2

COMP1

TPS55383

,, TPS55386

TERMINAL FUNCTIONS

TERMINAL

I/O

DESCRIPTION

NAME

NO.

Input supply to the high side gate driver for Output 1. Connect a 22-nF to 82-nF capacitor from this pin

to SW1. This capacitor is charged from the BP pin voltage through an internal switch. The switch is

BOOT1

2

I

turned ON during the OFF time of the converter. To slow down the turn ON of the internal FET, a small

resistor (1

Ω to 3 Ω) may be placed in series with the bootstrap capacitor.

Input supply to the high side gate driver for Output 2. Connect a 22-nF to 82-nF capacitor from this pin

to SW2. This capacitor is charged from the BP pin voltage through an internal switch. The switch is

BOOT2

15

I

turned ON during the OFF time of the converter. To slow down the turn ON of the internal FET, a small

resistor (1

Ω to 3 Ω) may be placed in series with the bootstrap capacitor.

Regulated voltage to charge the bootstrap capacitors. Bypass this pin to GND with a low ESR (4.7-

µF

BP

13

-

to 10-

µF X7R or X5R) ceramic capacitor.

Output of Error Amplifier for Output 1. A series connected R-C network from this pin to GND serves to

COMP1

8

O

compensate the feedback loop. See Feedback Loop Compensation Component Selection for further

information.

Output of Error Amplifier for Output 2. A series connected R-C network from this pin to GND serves to

COMP2

9

O

compensate the feedback loop. See Feedback Loop Compensation Component Selection for further

information.

Active low enable input for Output 1. If the voltage on this pin is greater than 1.55 V, Output 1 is

disabled (high-side switch is OFF). A voltage of less than 0.9 V enables Output 1 and allows soft start of

EN1

5

I

Output 1 to begin. An internal current source drives this pin to PVDD2 if left floating. Connect this pin to

GND for "always ON" operation.

Active low enable input for Output 2. If the voltage on this pin is greater than 1.55 V, Output 2 is

disabled (high-side switch is OFF). A voltage of less than 0.9 V enables Output 2 and allows soft start of

EN2

6

I

Output 2 to begin. An internal current source drives this pin to PVDD2 if left floating. Connect this pin to

GND for "always ON" operation.

Voltage feedback pin for Output 1. The internal transconductance error amplifier adjusts the PWM for

Output 1 to regulate the voltage at this pin to the internal 0.8-V reference. A series resistor divider from

FB1

7

I

Output 1 to ground, with the center connection tied to this pin, determines the value of the regulated

output voltage. Compensation for the feedback loop is provided externally to the device. See Feedback

Loop Compensation Component Selection section for further information.

Voltage feedback pin for Output 2. The internal transconductance error amplifier adjusts the PWM for

Output 2 to regulate the voltage at this pin to the internal 0.8-V reference. A series resistor divider from

FB2

10

I

Output 2 to ground, with the center connection tied to this pin, determines the value of the regulated

Output voltage. Compensation for the feedback loop is provided externally to the device. See Feedback

Loop Compensation Component Selection section for further information.

GND

4

-

Ground pin for the device. Connect directly to Thermal Pad.

Current limit adjust pin for Output 2 only. This function is intended to allow a user with asymmetrical

load currents (Output 1 load current much greater than Output 2 load current) to optimize component

ILIM2

11

I

scaling of the lower current output while maintaining proper component derating in a overcurrent fault

condition. The discrete levels are available as shown in Table 2, Current Limit Threshold Adjustment for

Output 2. Note: An internal 2-resistor divider (150-k

Ω each) connects BP to ILIM2 and to GND.

10

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Product Folder Link(s): TPS55383 TPS55386