LM3464MHX National Semiconductor Corporation, LM3464MHX Datasheet - Page 3

• Manufacturer Part Number: LM3464MHX
• Description: Lm3464 Led Driver With Dynamic Headroom Control And Thermal Control Interfaces
• Manufacturer: National Semiconductor Corporation

Pin
10
11
12
13
14
15
16
17
18
19
1
2
3
4
5
6
7
8
9
Pin Descriptions
Thermal_Cap
FAULT_CAP
Thermal
VLedFB
AGND
CDHC
Name
SYNC
VDHC
Faultb
DMIN
OutP
VCC
DR4
DR3
DR2
DR1
DIM
VIN
EN
Description
Synchronization signal output for cascade
operation
(Master-Slave configuration)
PWM dimming control
Thermal sensor input
Thermal dimming ramp capacitor
Head room control
Minimum thermal dimming duty control
Fault signal output
Signal ground
Fault delay capacitor
DHC time constant capacitor
DHC Output
Output voltage sense input
Internal regulator output
Enable input
Supply voltage
Channel 4 drain sense input
Channel 3 drain sense input
Channel 2 drain sense input
Channel 1 drain sense input
3
Application Information
Connect this pin to the DIM pin of other LM3464 to enable
cascade operation (multiple device). This pin should leave
open for single device operation.
Apply logic level PWM signal to this pin controls the average
brightness of the LED string. (<1.25V disable output).
Connect thermal sensor to this pin with bias accordingly to
facilitate thermal foldback and control the brightness of the
LED array.
Connect a capacitor across this pin and GND to define the
thermal dimming frequency.
Apply external voltage across this pin and ground to define the
minimum drain voltage. This pin is internal biased at 0.9V.
The voltage across this pin and GND defines the minimum
thermal dimming duty cycle.
Open Drain output, pull-down when FAULT condition
occurred.
Analog ground connection for internal circuitry. Must be
connected to PGND external to the package.
Connect to an external capacitor to program the fault response
time.
An external capacitor to ground programs the Dynamic
Headroom Control loop response time
Connect this pin to the voltage feedback input of primary power
supply to facilitate dynamic headroom control.
This pin senses the output voltage of the primary power supply.
This pin is the output terminal of the internal voltage regulator
and should be bypassed by a high quality 1uF ceramic
capacitor.
This pin serves as device enable input when logic level signal
is applied. (Active high with internal pull-up)
The input voltage should be in the range of 12V to 80V.
This pin senses the drain voltage of the external MOSFET of
channel 4 to facilitate DHC operation and fault detection.
This pin senses the drain voltage of the external MOSFET of
channel 3 to facilitate DHC operation and fault detection.
This pin senses the drain voltage of the external MOSFET of
channel 2 to facilitate DHC operation and fault detection.
This pin senses the drain voltage of the external MOSFET of
channel 1 to facilitate DHC operation and fault detection.
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