参数资料
型号: AS1582T
元件分类: 可调正电压单路输出LDO稳压器
英文描述: 1.25 V-6 V ADJUSTABLE POSITIVE LDO REGULATOR, 0.5 V DROPOUT, PSSO5
封装: TO-263, 5 PIN
文件页数: 3/4页
文件大小: 111K
代理商: AS1582T
Rev. 10/2/00
AS1582
BLOCK DIAGRAM
APPLICATIONS NOTES
The AS1582 is designed as a high performance and low cost
solution for application requiring a lower dropout than
traditional NPN regulators.
The AS1582 uses a separate input voltage VCTRL (VCTRL
VOUT+ 1.3V) to minimize the dropout voltage. This allows the
2.5V power for the load to come from a 3.3V system supply.
As added benefit this will reduce the heat dissipation, and
lower heatsink and cooling fan cost. A typical application
would use 5V for Vin and 3.3V for VCTRL from a motherboard
power supply to provide a nominal 2.5V output. Using the
sense pin allows to Kelvin measure the output, reducing
resistive-associated errors.
The AS1582 can power the 2.5V core voltage for
microprocessors such as Pentium
, P55C, AMD5k86
and K6
and the IBM PowerPC 603EV and 604EV
processors.
*The reduction of heat dissipation is a result of the increase of the regulator
efficiency (efficiency = VOUT / VIN).
Adjustable Regulator Design
1.25V reference voltage is being developed between the
SENSE pin and the ADJ pin of the AS1582. Adding two
external resistors (see fig 1.) will allow setting the output
voltage from 1.25V to 6V. R1 is chosen so that this current is
specified minimum load current of 10mA. R2 is given by the
formula: VOUT = VREF (1+ R2/R1) + IADJ (R2). The current
flowing from the ADJ pin is typically 50
A. This ADJ pin
contributes to the final VOUT but is usually neglected.
Connecting the sense pin to the top of the resistor divider will
improve load regulation.
Lowering Noise
Using the SENSE pin to Kelvin the load will increase accuracy
of the output voltage during load regulation. For the fixed
voltage devices, adding a capacitor at the GND pin will
improve transient response. This capacitor is chosen in the
range of 1
F to 0.1F and will depend on the amount of
output capacitance in the system.
PIN DESCRIPTION
1. Sense = Allows Kelvin sense of VOUT at the load. (Positive side of the reference voltage of the
device).
2. ADJ = Negative side of the reference voltage for the device. Adding a small bypass capacitor
from the ADJ pin to ground will improve the transient response.
3. VOUT = Power output of the device.
4. VCTRL = Supply pin for the control circuitry of the device. The current flow into this pin will be
about 1% of the output current. VCTRL must be between 1.0V and 1.3V greater than the output
voltage for the device to regulate.
5. VIN = Output load current is supplied through this pin. VIN must be between 0.1V and 0.8V
greater than the output voltage for the device to regulate.
(4) V
CTRL
V
IN (5)
S.O.A
V
OUT (3)
LIMIT
SENSE
CURRENT
LIMIT
AMPLIFIER
THERMAL OVERLOAD
VOLTAGE
REGULATION
AMPLIFIER
V
REF
SENSE (1)
ADJ (2)
相关PDF资料
PDF描述
AS1582U-3.3 3.3 V FIXED POSITIVE LDO REGULATOR, 0.5 V DROPOUT, PSFM5
AS1582U-2.8 2.8 V FIXED POSITIVE LDO REGULATOR, 0.5 V DROPOUT, PSFM5
AS1582U-2.5 2.5 V FIXED POSITIVE LDO REGULATOR, 0.5 V DROPOUT, PSFM5
AS1582T-3.3 3.3 V FIXED POSITIVE LDO REGULATOR, 0.5 V DROPOUT, PSSO5
AS1582T-2.8 2.8 V FIXED POSITIVE LDO REGULATOR, 0.5 V DROPOUT, PSSO5
相关代理商/技术参数
参数描述
AS1582T-2.5 制造商:未知厂家 制造商全称:未知厂家 功能描述:Analog IC
AS1582T-2.8 制造商:未知厂家 制造商全称:未知厂家 功能描述:Analog IC
AS1582T-3.3 制造商:未知厂家 制造商全称:未知厂家 功能描述:Analog IC
AS1582T-X 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:3A Ultra Low Dropout Voltage Regulator Fast Response, Adjustable & Fixed
AS1582U 制造商:未知厂家 制造商全称:未知厂家 功能描述:Analog IC