Datasheet LT1573 (Analog Devices)

FabricanteAnalog Devices
DescripciónLow Dropout PNP Regulator Driver
Páginas / Página16 / 1 — FEATURES. DESCRIPTIO. Low Cost Solution for High Current, Low Dropout. …
Formato / tamaño de archivoPDF / 183 Kb
Idioma del documentoInglés

FEATURES. DESCRIPTIO. Low Cost Solution for High Current, Low Dropout. Regulators. Fast Transient Response Needs Much Less

Datasheet LT1573 Analog Devices

Línea de modelo para esta hoja de datos

Versión de texto del documento

LT1573 Low Dropout PNP Regulator Driver
U FEATURES DESCRIPTIO

Low Cost Solution for High Current, Low Dropout
The LT ®1573 is a regulator driver IC designed to provide
Regulators
a low cost solution for applications requiring high current, ■
Fast Transient Response Needs Much Less
low dropout and fast transient response. When combined
Bulk Capacitance
with an external PNP power transistor, this device pro- ■
Latching Overload Protection Minimizes
vides load current up to 5A with dropout voltages as low
Heat Sink Size
as 0.35V. The LT1573 circuitry is designed for extremely ■
Precision Output Voltage (1%)
fast transient response. This greatly reduces bulk storage ■ Single Supply Operation: VIN = 2.8V to 10V capacitance when the regulator is used in applications ■ Small Surface Mount Package with fast, high current load transients. ■ Capable of Very Low Dropout Voltage (<0.2V) To keep cost and complexity low, the LT1573 uses a new ■ Fixed or Adjustable Outputs time-delayed latching overcurrent protection technique ■ Shutdown that requires no external current sense resistor. Base drive
U
is limited for instantaneous protection, and a time-delayed
APPLICATIO S
latch protects the regulator from continuous short ■ 3.3V to 2.5V Regulators circuits. ■ Microprocessor Power Sources The LT1573 is available as an adjustable regulator with an ■ Post Regulator for Switching Supplies output range of 1.27V to 6.8V and with fixed output ■ High Efficiency Linear Regulators voltages of 2.5V, 2.8V and 3.3V. Output accuracy is better ■ Ultralow Dropout Regulators than 1% to meet the critical regulation requirement of fast ■ Low Voltage Linear Regulators microprocessors. A special 8-pin, fused-lead surface mount package is used to minimize regulator footprint and pro- , LTC and LT are registered trademarks of Linear Technology Corporation. vide adequate heat sinking.
U TYPICAL APPLICATIO
CC 100pF RC
Transient Response for
1k FB COMP
0.2A to 5A Output Load Step
LATCH VOUT LT1573 + CTIME SHDN VIN RD RB 50mV/DIV 24Ω 50Ω QOUT GND DRIVE MOTOROLA D45H11 VIN VOUT 5V 3.3V R1 COUT1 CIN + + C 1.6k OUT2 1µF 100µF 220µF 2.5A/DIV CER LOAD TANT TANT × 24 R2 1k GND 10µs/DIV 1573 F01a VOUT = 1.265V (1 + R1/R2) 1573 F01 FOR T < 45°C, COUT1 = 24 × 1µF Y5V CERAMIC SURFACE MOUNT CAPACITORS. FOR T > 45°C, COUT1 = 24 × 1µF X7R CERAMIC SURFACE MOUNT CAPACITORS. PLACE COUT1 IN THE MICROPROCESSOR SOCKET CAVITY
Figure 1. 3.3V, 5A Microprocessor Supply
sn1573 1573fas 1