L5994 - L5994A

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PIN DESCRIPTION

N°

Name

Function

1

H1STRAP

Section 1 bootstrap capacitor connection. A bootstrap capacitor must be connected between

this pin and pin H1SRC to supply the H1GATE driver.

2

Vin

Device supply voltage.

3

SREG5

Internal logic supply. It must be connected to PREG5 pin through a R-C low-pass filter.

4

V5SW

Alternative supply voltage for the internal 5V regulator. If its voltage is greater than 4.5V, the

internal regulator is supplied via this pin. If left floating, the regulator is supplied through the

Vin pin.

5

V1SNS

This pin connects the (-) input of section 1 current sense comparator. It must be connected

6

I1SNS

This pin connects the (+) input of section 1 current sense comparator. It must be connected

7

COMP1

Feedback input for section 1. It must be connected directly or through a resistor divider to the

output of the section 1.

8

SOFT1

Soft start connection for section 1. The soft start time is programmed by an external capacitor

connected between this pin and SGND. Approximatively 0.7ms/nF.

9

CRST

Used for start-up and shut-down timing. A capacitor must be connected between this pin and

SGND defining a time of 1.47ms/nF.

10

PWROK1

Power Good open drain diagnostic signal. This output is in high inpedence when sect. 1 is

enabled and running properly after a delay defined by the CRST capacitor. When not used

may be left floating.

11

RUN1

Control input to enable / disable the section 1. A high logic level (>2.4V) enables this section,

a low level (<0.8V) shuts it down.

12

Vref

Internal 2.5V high accuracy voltage generator. It can source 5mA to external load. Bypass to

SGND with a 4.7uF electrolytic capacitor to reduce noise.

13

SGND

Signal ground. Reference for internal logic circuitry. It must be routed separately from high

current returns.

14

NOSKIP

Pulse skipping mode control. A high logic level (>2.4V) disables pulse skipping at low load

current, a low level (<0.8V) enables it.

15

OSC

Oscillator frequency control: connect to 2.5V to select 300kHz operation, connect to ground or

to 5V for 200kHz operation.

A proper external signal can synchronise the oscillator

16

RUN2

Control input to enable / disable the section 2. A high logic level (>2.4V) enables this section,

a low level (<0.8V) shuts it down.

17

SOFT2

Soft start connection for section 2. The soft start time is programmed by an external capacitor

connected between this pin and SGND. Approximatively 0.7ms/nF.

18

COMP2

Feedback input for section 2. It must be connected directly or through a resistor divider to the

output of the section 2.

19

I2SNS

This pin connects the (+) input of section 2 current sense comparator. It must be connected

20

V2SNS

This pin connects the (-) input of section 2 current sense comparator. It must be connected