Datasheet LT1534 (Analog Devices)
| Fabricante | Analog Devices |
| Descripción | Ultralow Noise 2A Switching Regulators |
| Páginas / Página | 16 / 1 — FEATURES. DESCRIPTIO. Greatly Reduced Conducted and Radiated EMI. Low … |
| Formato / tamaño de archivo | PDF / 216 Kb |
| Idioma del documento | Inglés |
FEATURES. DESCRIPTIO. Greatly Reduced Conducted and Radiated EMI. Low Switching Harmonic Content
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LT1534/LT1534-1 Ultralow Noise 2A Switching Regulators
U FEATURES DESCRIPTIO
■
Greatly Reduced Conducted and Radiated EMI
The LT®1534/LT1534-1 are a new class of switching regula- ■
Low Switching Harmonic Content
tor designed to reduce conducted and radiated electromag- ■
Independent Control of Switch Voltage and
netic interference (EMI). Ultralow noise and EMI are achieved
Current Slew Rates
by providing user control of the output switch slew rates. ■ 2A Current Limited Power Switch Voltage and current slew rates can be independently pro- ■ Regulates Positive and Negative Voltages grammed to optimize switcher harmonic content versus ■ 20kHz to 250kHz Oscillator Frequency efficiency. The LT1534/LT1534-1 can reduce high frequency ■ Easily Synchronized to External Clock harmonic power by as much as 40dB with only minor losses ■ Wide Input Voltage Range: 2.7V to 23V in efficiency. ■ Low Shutdown Current: 12µA Typical The LT1534/LT1534-1 utilize a current mode architecture ■ Easier Layout than with Conventional Switchers optimized for low noise boost topologies. The ICs include a
U
2A power switch along with all necessary oscillator, control
APPLICATIO S
and protection circuitry. Unique error amp circuitry can regulate both positive and negative voltages. The internal ■ Precision Instrumentation Systems oscillator may be synchronized to an external clock for more ■ Isolated Supplies for Industrial Automation accurate placement of switching harmonics. Protection fea- ■ Medical Instruments tures include cycle-by-cycle current limit protection, under- ■ Wireless Communications voltage lockout and thermal shutdown. ■ Single Board Data Acquisition Systems Low minimum supply voltage and low supply current during shutdown make the LT1534/LT1534-1 well suited for por- table applications. The LT1534/LT1534-1 are available in the 16-pin narrow SO package. , LTC and LT are registered trademarks of Linear Technology Corporation.
U TYPICAL APPLICATION
L1 L3 3.3V 1N5817 50µH A 50µH B 5V 15 + 650mA C C1 IN + + 33µF C2 V 47µF 12 IN 2 10Ω 6.3V 6.3V 47µF
5V Output Noise (BW = 100MHz)
SHDN COL 4 ×2 SYNC OPTIONAL L2 1nF 3300pF 3 PGND 5 A CT LT1534-1 14 24k 50mV/DIV R 16.9k VSL 6 RT 13 24k RCSL 7.5k 11 7 1534 TA01 VC FB B GND NFB 220pF 6.8k 2mV/DIV 2.49k 1,8, 10 CIN: MATSUSHITA ECGCOJB330 9,16 C1, C2: MATSUSHITA ECGCOJB47O 15nF L1, L3: COILTRONICS CTX50-4 L2: COILCRAFT B08T (28nH) OR PC TRACE 1534 TA02 10µs/DIV
Figure 1. Low Noise 3.3V to 5V Boost Converter
1
U FEATURES DESCRIPTIO
■
Greatly Reduced Conducted and Radiated EMI
The LT®1534/LT1534-1 are a new class of switching regula- ■
Low Switching Harmonic Content
tor designed to reduce conducted and radiated electromag- ■
Independent Control of Switch Voltage and
netic interference (EMI). Ultralow noise and EMI are achieved
Current Slew Rates
by providing user control of the output switch slew rates. ■ 2A Current Limited Power Switch Voltage and current slew rates can be independently pro- ■ Regulates Positive and Negative Voltages grammed to optimize switcher harmonic content versus ■ 20kHz to 250kHz Oscillator Frequency efficiency. The LT1534/LT1534-1 can reduce high frequency ■ Easily Synchronized to External Clock harmonic power by as much as 40dB with only minor losses ■ Wide Input Voltage Range: 2.7V to 23V in efficiency. ■ Low Shutdown Current: 12µA Typical The LT1534/LT1534-1 utilize a current mode architecture ■ Easier Layout than with Conventional Switchers optimized for low noise boost topologies. The ICs include a
U
2A power switch along with all necessary oscillator, control
APPLICATIO S
and protection circuitry. Unique error amp circuitry can regulate both positive and negative voltages. The internal ■ Precision Instrumentation Systems oscillator may be synchronized to an external clock for more ■ Isolated Supplies for Industrial Automation accurate placement of switching harmonics. Protection fea- ■ Medical Instruments tures include cycle-by-cycle current limit protection, under- ■ Wireless Communications voltage lockout and thermal shutdown. ■ Single Board Data Acquisition Systems Low minimum supply voltage and low supply current during shutdown make the LT1534/LT1534-1 well suited for por- table applications. The LT1534/LT1534-1 are available in the 16-pin narrow SO package. , LTC and LT are registered trademarks of Linear Technology Corporation.
U TYPICAL APPLICATION
L1 L3 3.3V 1N5817 50µH A 50µH B 5V 15 + 650mA C C1 IN + + 33µF C2 V 47µF 12 IN 2 10Ω 6.3V 6.3V 47µF
5V Output Noise (BW = 100MHz)
SHDN COL 4 ×2 SYNC OPTIONAL L2 1nF 3300pF 3 PGND 5 A CT LT1534-1 14 24k 50mV/DIV R 16.9k VSL 6 RT 13 24k RCSL 7.5k 11 7 1534 TA01 VC FB B GND NFB 220pF 6.8k 2mV/DIV 2.49k 1,8, 10 CIN: MATSUSHITA ECGCOJB330 9,16 C1, C2: MATSUSHITA ECGCOJB47O 15nF L1, L3: COILTRONICS CTX50-4 L2: COILCRAFT B08T (28nH) OR PC TRACE 1534 TA02 10µs/DIV
Figure 1. Low Noise 3.3V to 5V Boost Converter
1