CAT4238: LED Boost Converter, High Efficiency
The CAT4238 is a DC-DC step-up converter that delivers an accurate constant current ideal for driving LEDs. Operation at a fixed switching frequency of 1 MHz allows the device to be used with small value external ceramic capacitors and inductor. LEDs connected in series are driven with a regulated current set by the external resistor R1. LED currents up to 40 mA can be supported over a wide range of input supply voltages up to 5.5 V, making the device ideal for battery-powered applications. The CAT4238 high-voltage output stage is perfect for driving mid-size and large panel displays containing up to ten white LEDs in series. LED dimming can be done by using a DC voltage, a logic signal, or a pulse width modulation (PWM) signal. The shutdown input pin allows the device to be placed in power-down mode with 'zero' quiescent current. In addition to thermal protection and overload current limiting, the device also enters a very low power operating mode during 'Open LED' fault conditions.
Features- Drives High Voltage LED strings (38 V)
- Up to 87% Efficiency
- Low Quiescent Ground Current 0.6 mA
- Adjustable Output Current
- 1 MHz Fixed Frequency Low noise Operation
- Soft start “in-rush” current limiting
- Shutdown current less than 1 µA
- Open LED Overvoltage Protection
- Automatic Shutdown at 1.9 V (UVLO)
- Thermal overload protection
- Mid-size and Large Panel Displays
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Applications- LED Drive in battery Powered Devices
| End Products- GPS Navigation Systems
- Portable Gaming Systems
- Digital Still Cameras
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Data Sheets (1)
Evaluation Board Documents (5)
Package Drawings (1)
Evaluation/Development Tool Information
| Product | Status | Compliance | Short Description |
|---|
| CAT4238AGEVB | Active | Pb-free | High Voltage CMOS Constant-Current DC-DC Converter Evaluation Board |
Order Information
| Product | Status | Compliance | Package | MSL* | Container | Budgetary Price/Unit |
|---|
| CAT4238TD-GT3 | Active | Pb-free
Halide free | TSOT-23-5 | 419AE | 1 | Tape and Reel | 3000 | $0.48 |
Specifications
| Product | Topology | VIN Min (V) | VIN Max (V) | VO Max (V) | IO Max (mA) | fSW Typ (kHz) |
|---|
| CAT4238TD-GT3 | Step-Up | 2 | 5.5 | 38 | 100 | 1000 |
