A Product Line of
Diodes Incorporated
PAM99700
UNIVERSAL HIGH BRIGHTNESS LED DRIVER
Description |
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Pin Assignments |
The PAM99700 is an open loop current mode control LED driver IC. The PAM99700 can be programmed to operate in either a constant frequency or constant off-time mode. It includes a 12 - 500V regulator which allows it to work from a wide range of input voltages without the need for an external low voltage supply. The PAM99700 includes a PWM dimming input that can accept an external control signal with a duty ratio of 0 - 100% and a frequency of up to a few kilohertz. It also includes a 0 - 250mV linear dimming input which can be used for linear dimming of the LED current.
The PAM99700 is ideally suited for buck LED drivers. Since the PAM99700 operates in open loop current mode control, the controller achieves good output current regulation without the need for any loop compensation. PWM dimming response is limited only by the rate of rise and fall of the inductor current, enabling very fast rise and fall times. The PAM99700 requires only three external components (apart from the power stage) to produce a controlled LED current making it an ideal solution for low cost LED drivers.
Features
•Switch Mode Controller for Single Switch LED Drivers
•Open Loop Peak Current Controller
•Constant Frequency or Constant Off-Time Operation
•Linear and PWM Dimming Capability
•Requires Few External Components for Operation
•Application From a Few mA to More than 1A Output
Applications
• DC/DC or AC/DC LED Driver Applications
• RGB Backlighting LED Driver
• Back Lighting of Flat Panel Displays
• General Purpose Constant Current Source
• Signage and Decorative LED Lighting
PAM99700 |
1 of 12 |
October 2012 |
Document number: DSxxxxx Rev. 1 - 1 |
www.diodes.com |
© Diodes Incorporated |
A Product Line of
Diodes Incorporated
PAM99700
Typical Applications Circuit
Pin Descriptions
Pin |
Pin Number |
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Name |
SOP-8 |
SOP-16 |
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VIN |
1 |
1 |
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CS |
2 |
4 |
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GND |
3 |
5 |
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GATE |
4 |
8 |
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PWMD |
5 |
9 |
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VDD |
6 |
12 |
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LD |
7 |
13 |
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RT |
8 |
14 |
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NC |
— |
2, 3, 6, 7, |
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10, 11, 15, 16 |
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Function
This pin is the input of a 12V-500V regulator.
This pin is the current sense pin used to sense the FET current by means of an external sense resistor. When this pin exceeds the lower of either the internal 250mV or the voltage at the LD pin, the gate output goes low.
Ground return for all internal circuitry. This pin must be electrically connected to the ground of the power train.
This pin is the output gate driver for an external N-Channel power MOSFET.
This is the PWM dimming input of the IC. When this pin is pulled to GND, the gate driver is turned off. When the pin is pulled high, the gate driver operates normally.
This is the power supply pin for all internal circuits. It must be bypassed with a low ESR capacitor to GND (~ 10μF).
This pin is the linear dimming input an d sets the current sense threshold as long as the voltage at the pin is less than 250mV (typ).
This pin sets the oscillator frequency. When a resistor is connected between RT and GND, the PAM99700 operates in constant frequency mode. When the resistor is connected between RT and GATE, the IC operates in constant off-time mode.
Not connected.
PAM99700 |
2 of 12 |
October 2012 |
Document number: DSxxxxx Rev. 1 - 1 |
www.diodes.com |
© Diodes Incorporated |
A Product Line of
Diodes Incorporated
PAM99700
Functional Block Diagram
Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified.)
These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may affect device reliability. All voltages are with respect to ground.
Parameter |
Rating |
Unit |
Maximum Junction Temperature |
150 |
|
Storage Temperature |
-65 to +150 |
°C |
Soldering Temperature |
300, 5sec |
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Recommended Operating Conditions (@TA = +25°C, unless otherwise specified.)
Parameter |
Rating |
Unit |
Supply Voltage |
12 to 500 |
V |
Ambient Temperature Range |
-40 to +85 |
°C |
Junction Temperature Range |
-40 to +125 |
°C |
Thermal Information
Parameter |
Package |
Symbol |
Max |
Unit |
|
Thermal Resistance (Junction to Ambient) |
SOP-8 |
θJA |
115 |
°C/W |
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SOP-16 |
110 |
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PAM99700 |
3 of 12 |
October 2012 |
Document number: DSxxxxx Rev. 1 - 1 |
www.diodes.com |
© Diodes Incorporated |
A Product Line of
Diodes Incorporated
PAM99700
Electrical Characteristics (@TA = +25°C, unless otherwise specified.)
Parameter |
Symbol |
Test Conditions |
Min |
Typ |
Max |
Units |
|
Input Voltage Range |
VINDC |
DC Input Voltage |
12 |
|
500 |
V |
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Shutdown Mode Supply Current |
IINSD |
Pin PWMD to GND |
|
0.1 |
|
mA |
|
Internally Regulated Voltage |
VDD |
VIN > 20V |
6 |
10 |
|
V |
|
Current Sense Pul-In Threshold Voltage |
VCS,TH |
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|
250 |
|
mV |
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Current Sense Blanking Interval |
TBLANK |
|
|
250 |
|
Ns |
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Gate Sourcing Current |
ISOURCE |
VGATE = 0V |
0.2 |
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|
A |
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Gate Sinking Current |
ISINK |
VGATE = VDD |
0.2 |
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|
A |
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Gate Output Rise Time |
tRISE |
CGATE = 1nF |
|
30 |
50 |
ns |
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Gate Output Fall Time |
tTALL |
CGATE = 1nF |
|
30 |
50 |
ns |
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Oscillator Frequency |
fOSC |
RT = 510kΩ |
37 |
41 |
49 |
kHz |
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RT = 226kΩ |
74 |
92 |
110 |
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EN Threshold High |
VEH |
VIN = 12V to 500V |
2.4 |
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V |
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EN Threshold Low |
VEL |
VIN = 12V to 500V |
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1.0 |
V |
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Over Temperature Protection |
OTP |
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|
160 |
|
°C |
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OTP Hysteresis |
OTH |
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|
50 |
|
°C |
PAM99700 |
4 of 12 |
October 2012 |
Document number: DSxxxxx Rev. 1 - 1 |
www.diodes.com |
© Diodes Incorporated |
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