TPS92511 Datasheet, PDF (1/31 Pages) Texas Instruments – 500-mA, 65-V Common Anode Constant Current Buck LED Driver Without External Current Sensing Resistor

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TPS92511
SNVS901A – MARCH 2014 – REVISED MAY 2014
TPS92511 500-mA, 65-V Common Anode Constant Current Buck LED Driver Without
External Current Sensing Resistor
1 Features
•1 Wide Input Voltage Range: 4.5 V to 65 V
• Requires NO External Current Sensing Resistor
• Requires NO External Loop Compensation
• Ease of Use, Needs Minimum 5 Components
• 1000:1 Contrast Ratio Feasible
• Single Layer PCB Feasible
• Can Work as High Voltage Buck Regulators
• Can Work as Linear Current Shunt Regulators
• Integrated Low-side N-channel MOSFET
• LED Current Programmable up to 0.5 A
• Typically ±3.6% LED Current Accuracy
• Switching Frequency Programmable From 50 kHz
to 500 kHz
• Current Limit Protection
• VCC Under-voltage Lock-out
• Thermal Shutdown Protection
• Support Analog Dimming and Thermal Foldback
• Power Enhanced SOIC-8 Exposed Thermal Pad
Package (HSOP-8)
2 Applications
• High Power LED Driver
• Architectural Lighting
• Office Troffer
• Automotive Lighting
• MR-16 LED Lamp
C_VCC
Simplified Application
V_IN
TPS92511
VCC
PGND
VIN
LED string
I_LED
LX
D1
L1
R_IADJ
IADJ
GND
DIM
PWM dimming signal
FS
R_FS
3 Description
The TPS92511 is an easy to use 65V constant
current buck converter for driving a single LED string
with current up to 0.5A and efficiency up to 95%.
Only 5 external components are required for basic
operation and single layer PCB layout is feasible
because of the integration of a N-MOSFET, no
external current sensing resistor, no external
compensation and the proper terminal assignment. A
high-value external resistor programs the LED current
so that fine tuning of the LED current can be
achieved. Another high-value external resistor
programs a constant switching frequency from 50kHz
to 500kHz. EMI design becomes easier as a result of
constant switching frequency. The TPS92511
provides a wide input voltage range from 4.5V to
65V. By adding simple external circuits, the device
can handle applications with even higher input
voltages.
The TPS92511 employs a proprietary control scheme
to regulate the LED current without the need of
sensing the LED current directly. It applies a floating
buck topology with a low-side N-channel power
MOSFET, which does not need boot-strapping
capacitor. For multiple channel systems, the floating
buck topology together with the proprietary control
scheme allows a common-anode connection of the
LED strings without an external current sensing
network. This significantly reduces the number of
wiring and as well as overall manufacturing cost.
The TPS92511 has very fast PWM dimming response
time. For example, if the switching frequency is 500
kHz, the minimum DIM pulse width is 6µs and the
dimming frequency is 150Hz, a contrast ratio of more
than 1000:1 can be achieved.
The TPS92511 is available in the Power Enhanced
SOIC-8 exposed thermal pad package.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
TPS92511
HSOP (8)
4.89mm × 3.90mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.