PT4121E
60V Step-down High Brightness
LED Controller
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PT4121E_DS_Rev EN 1.4
GENERAL DESCRIPTION
The PT4121E is a high efficiency step-down
controller. It is designed to operate in continuous
conduction mode and drive single or multiple
series connected LED efficiently from a voltage
source higher than the total LED chain voltage. It
operates with a wide input voltage from 6V to 60V
and provides an externally adjustable output
current.
The PT4121E includes a high-side output
current sense circuit, which uses an external
resistor to set the nominal average output current,
and a dedicated DIM input accepts either a DC
voltage or PWM dimming.
The PT4121E is available in SOT23-6 or SOP-8
packages.
FEATURES
๏ฌ Less external components
๏ฌ Wide input voltage range: 6V to 60V
๏ฌ High efficiency (up to 97%)
๏ฌ Single pin on/off and brightness control using
DC Voltage or PWM
๏ฌ Up to 1MHz switching frequency
๏ฌ Adjustable Constant LED Current
๏ฌ Typical 3% output current accuracy
๏ฌ High-Side Current Sense
๏ฌ Hysteretic Control: No need compensation
๏ฌ Inherent R
CS
open protection
๏ฌ Inherent open-circuit LED protection
๏ฌ Inherent short-circuit LED protection
๏ฌ Over Temperature Protection
APPLICATIONS
๏ฌ Low voltage halogen replacement LEDs
๏ฌ Automotive/Decorative lighting
๏ฌ Low voltage industrial lighting
๏ฌ LED back-up lighting
๏ฌ Signs/Emergency lighting
๏ฌ SELV lighting
๏ฌ LCD TV backlighting
TYPICAL APPLICATION CIRCUIT
PT4121E
60V Step-down High Brightness
LED Controller
CRM ICBG (WUXI) CO., LTD. WWW.CRMICRO.COM Page 2
PT4121E_DS_Rev EN 1.4
ORDERING INFORMATION
PACKAGE
ORDERING PART
NUMBER
TRANSPORT MEDIA MARKING
SOT23-6 PT4121EE23F
Tape and Reel
3000 units
4121E
SOP-8 PT4121EESOH
Tape and Reel
4000 units
PT4121E
xxxxxX
PIN ASSIGNMENT
PIN DESCRIPTIONS
PIN No.
SOP-8
PIN No.
SOT23-6
PIN
NAMES
DESCRIPTION
1 NC Not connected.
2 6 VCC
Internal Regulator Output. Connect a 1ยตF decoupling cap from this
pin to ground.
3 5 DRV
Gate-Driver Output. Connect this pin to the gate of the external
MOSFET.
4 4 GND Signal and power ground. Connect directly to ground plane.
5 3 DIM
Logic level dimming input. Drive DIM low to turn off the current
regulator. Drive DIM high to enable the current regulator.
6 1 VIN
Input Supply Pin. Connect a decoupling capacitor from VIN pin to
GND.
7 2 CSN
LED Current Sense Input. Connect a current-sense resistor that
programs LED average current to the VIN pin.
8 NC Not connected.