Datasheet LT3439 (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | Slew Rate Controlled Ultralow Noise 1A Isolated DC/DC Transformer Driver |
| Seiten / Seite | 12 / 1 — FEATURES. DESCRIPTIO. Reduced Conducted and Radiated EMI. Single Resistor … |
| Dateiformat / Größe | PDF / 196 Kb |
| Dokumentensprache | Englisch |
FEATURES. DESCRIPTIO. Reduced Conducted and Radiated EMI. Single Resistor Control of Output Switch Voltage
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LT3439 Slew Rate Controlled Ultralow Noise1A Isolated DC/DC Transformer Driver
U FEATURES DESCRIPTIO
■
Reduced Conducted and Radiated EMI
The LT®3439 is a push-pull DC/DC transformer driver that ■
Single Resistor Control of Output Switch Voltage
reduces conducted and radiated electromagnetic interfer-
and Current Slew Rates
ence (EMI). Ultralow noise and EMI are achieved by ■
Cross Conduction Prevention Circuitry
controlling the output switch voltage and current slew ■
Two 1A Current Limited Power Switches
rates. Slew rates are user adjustable to optimize output ■ Low Minimum Supply Voltage: 2.8V noise versus efficiency. The LT3439 can reduce high ■ Low Shutdown Current: < 20µA frequency harmonic content by as much as 40dB with only ■ 50% Duty Cycle a minor decrease in efficiency. ■ 20kHz to 250kHz Oscillator Frequency The LT3439 includes two 1A current limited power switches ■ Synchronizable to 300kHz to ensure start-up under heavy loads. It also includes an ■ Overcurrent and Overtemperature Protected oscillator that can be synchronized to an external clock for more accurate placement of switcher harmonics. Protec-
U
tion features include current limiting, undervoltage lock-
APPLICATIO S
out, thermal shutdown and cross conduction prevention ■ Low Noise Isolated Supplies circuitry. ■ Radio and Telecom Supplies The LT3439 is available in a thermally enhanced 16-pin ■ Distributed Supplies TSSOP with an exposed backside. ■ Medical Instruments ■ Precision Instruments , LTC and LT are registered trademarks of Linear Technology Corporation. ■ Low Noise Filament Supplies
U TYPICAL APPLICATIO Low Noise 5V to 5V Push-Pull DC/DC Transformer 5V Output Noise
OPTIONAL V D1 IN L1 33µH T1 A B VOUT 5V C 5V IN 13 C1 C2 22µF • • 500mA 47µF 47µF 10V VIN B 11 3 6.3V 6.3V SHDN COL A 200µV/DIV • • LT3439 5 14 SYNC COL B 6 CT D2 680pF 7 4 CIN: MURATA GRM235Y5V226Z10 R R C1, C2: TDK C4532X5R0J476M T SL A 16.9k D1, D2: MBR0520 GND PGND 34k L1: TDK SLF6028T-330MR69 20mV/DIV 10 1, 16 T1: COILTRONICS 15835 3439 TA01 5µs/DIV 3439 TA01b sn3439 3439fs 1
U FEATURES DESCRIPTIO
■
Reduced Conducted and Radiated EMI
The LT®3439 is a push-pull DC/DC transformer driver that ■
Single Resistor Control of Output Switch Voltage
reduces conducted and radiated electromagnetic interfer-
and Current Slew Rates
ence (EMI). Ultralow noise and EMI are achieved by ■
Cross Conduction Prevention Circuitry
controlling the output switch voltage and current slew ■
Two 1A Current Limited Power Switches
rates. Slew rates are user adjustable to optimize output ■ Low Minimum Supply Voltage: 2.8V noise versus efficiency. The LT3439 can reduce high ■ Low Shutdown Current: < 20µA frequency harmonic content by as much as 40dB with only ■ 50% Duty Cycle a minor decrease in efficiency. ■ 20kHz to 250kHz Oscillator Frequency The LT3439 includes two 1A current limited power switches ■ Synchronizable to 300kHz to ensure start-up under heavy loads. It also includes an ■ Overcurrent and Overtemperature Protected oscillator that can be synchronized to an external clock for more accurate placement of switcher harmonics. Protec-
U
tion features include current limiting, undervoltage lock-
APPLICATIO S
out, thermal shutdown and cross conduction prevention ■ Low Noise Isolated Supplies circuitry. ■ Radio and Telecom Supplies The LT3439 is available in a thermally enhanced 16-pin ■ Distributed Supplies TSSOP with an exposed backside. ■ Medical Instruments ■ Precision Instruments , LTC and LT are registered trademarks of Linear Technology Corporation. ■ Low Noise Filament Supplies
U TYPICAL APPLICATIO Low Noise 5V to 5V Push-Pull DC/DC Transformer 5V Output Noise
OPTIONAL V D1 IN L1 33µH T1 A B VOUT 5V C 5V IN 13 C1 C2 22µF • • 500mA 47µF 47µF 10V VIN B 11 3 6.3V 6.3V SHDN COL A 200µV/DIV • • LT3439 5 14 SYNC COL B 6 CT D2 680pF 7 4 CIN: MURATA GRM235Y5V226Z10 R R C1, C2: TDK C4532X5R0J476M T SL A 16.9k D1, D2: MBR0520 GND PGND 34k L1: TDK SLF6028T-330MR69 20mV/DIV 10 1, 16 T1: COILTRONICS 15835 3439 TA01 5µs/DIV 3439 TA01b sn3439 3439fs 1