Zxld1370, Pin descriptions – Diodes ZXLD1370 User Manual
Page 3
ZXLD1370
Document number: DS32165 Rev. 5 - 2
3 of 39
September 2012
© Diodes Incorporated
ZXLD1370
A Product Line of
Diodes Incorporated
Pin Descriptions
Pin Name
Pin
Type
(Note 4)
Function
ADJ 1 I
Adjust input (for dc output current control).
Connect to REF to set 100% output current.
Drive with dc voltage (125mV<V
ADJ
< 2.5V) to adjust output current from 10% to 200% of set value.
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.
SGND
6
P
Signal ground (Connect to 0V)
PGND
7
P
Power ground - Connect to 0V and pin 8 to maximize copper area
N/C 8 -
Not Connected internally – recommend connection to pin 7, (PGND), to maximize PCB copper for
thermal dissipation
N/C 9
Not Connected internally – recommend connection pin 10 (GATE) to permit wide copper trace to gate
of MOSFET
GATE
10
O
Gate drive output to external NMOS transistor – connect to pin 9
V
AUX
11 P
Auxiliary positive supply to internal switch gate driver.
Connect to V
IN
, or auxiliary supply from 6V to 15V supply to reduce internal power dissipation (Refer
to application section for more details)
Decouple to ground with capacitor close to device (refer to Applications section)
V
IN
12 P
Input supply to device (6V to 60V).
Decouple to ground with capacitor close to device (refer to Applications section)
ISM 13 I
Current monitor input. Connect current sense resistor between this pin and V
IN
The nominal voltage across the resistor is 225mV
FLAG 14 O
Flag open drain output.
Pin is high impedance during normal operation
Pin switches low to indicate a fault, or warning condition
PWM 15 I
Digital PWM output current control.
Pin driven either by open Drain or push-pull 3.3V or 5V logic levels.
Drive with frequency higher than 100Hz to gate output ‘on’ and ‘off’ during dimming control.
The device enters standby mode when PWM pin is driven with logic low level for more than 15ms
nominal (Refer to application section for more details)
GI 16 I
Gain setting input.
Used to set the device in Buck mode or Boost, Buck-boost modes
Connect to ADJ in Buck mode operation
For Boost and Buck-boost modes, connect to resistive divider from ADJ to SGND. This defines the ratio
of switch current to LED current (see application section). The GI pin has an internal clamp that limits
the internal
node to less than 3V. This provides some failsafe should they get overdriven
EP
PAD
P
Exposed paddle. Connect to 0V plane for electrical and thermal management
Note:
4. Type refers to whether or not pin is an Input, Output, Input/Output or power supply pin.