ZXLD1370Q

Document number: DS37117 Rev. 1 - 2

2 of 37

www.diodes.com

August 2015

© Diodes Incorporated

ZXLD1370Q

Functional Block Diagram

Fast

current

monitor

Accurate

current

monitor

-

Error amp

Demand

current

source

Frequency &

hysteresis

control

Gate

driver

ADJ

COMPIN

VIN

+

-

LOAD

L

GI

D

VIN

ISENSE

VAUX

VAUX

PWM

SGND

PGND

REF

TADJ

Reference

STATUS

FLAG

Error

report

Pin Descriptions

Pin Name

Pin

Type

(Note 5)

Function

ADJ

1

I

Adjust input (for DC output current control).

Connect to REF to set 100% output current.

The ADJ pin has an internal clamp that limits the internal node to less than 3V. This provides some

failsafe should they get overdriven.

REF

2

O

Internal 1.25V reference voltage output

TADJ

3

I

Temperature Adjust input for LED thermal current control

Connect thermistor/resistor network to this pin to reduce output current above a preset temperature

threshold.

Connect to REF to disable thermal compensation function. (See section on thermal control.)

SHP

4

I/O

Shaping capacitor for feedback control loop

Connect 100pF ±20% capacitor from this pin to ground to provide loop compensation.

STATUS

5

O

Operation status output (analog output)

Pin is at 4.5V (nominal) during normal operation.

Pin switches to a lower voltage to indicate specific operation warnings or fault conditions. (See section

on STATUS output.)

Status pin voltage is low during shutdown mode.

Note:

5.

Type refers to whether or not pin is an Input, Output, Input/Output or power supply pin.