GM66150 Просмотр технического описания (PDF) - Gamma Microelectronics Inc.

Номер в каталоге

Компоненты Описание

Список матч

GM66150

1.5A ULTRA LOW DROPOUT VOLTAGE REGULATORS

Gamma Microelectronics Inc. 

GM66150 Series

1.5A ULTRA LOW DROPOUT VOLTAGE

REGULATORS

Application Information

The GM66150 series is a high performance low-dropout voltage regulator suitable for all moderate to high

current/voltage regulator applications. The 350mV dropout voltage at full load makes it especially valuable

in battery powered systems and as high efficiency noise filters in “post-regulator” applications.

Unlike older NPN-pass transistor designs, dropout performance of the PNP output of these devices is

limited merely by the low VCE saturation voltage. The GM66150 family of regulators is fully protected from

damage due to fault conditions. Current limiting is provided. This limiting is linear; output current under

overload conditions is constant.

Thermal shutdown disables the device when the die temperature exceeds the 125°C maximum safe

operating temperature. Transient protection allows device survival even when the input voltage spikes

between -20V and +60V. When the input voltage exceeds about 35V to 40V, the over voltage sensor

temporarily disables the regulator.

VIN

IN

OUT

VOUT

GND

Figure 1.Linear regulators require only two capacitors for operation.

Thermal Design

Linear regulators are simple to use. The most complicated design parameters to consider are thermal

characteristics. Thermal design requires the following application-specific parameters:

• Maximum ambient temperature, TA

• Output Current, IOUT

• Output Voltage, VOUT

• Input Voltage, VIN

First, we calculate the power dissipation of the regulator from these numbers and the device

parameters from this datasheet.

PD = IOUT X (1.01VIN - VOUT), Where the ground current is approximated by 1% of IOUT.

Then the heat sink thermal resistance is determined with this formula:

TJMAX – TA

θSA =

– (θJC+θCS), where TJMAX ≤125°C and θCS is between 0 and 20°C/W

PD

Capacitor Requirements

For stability and minimum output noise, a capacitor on the regulator output is necessary. The value of this

capacitor is dependent upon the output current; lower currents allow smaller capacitors. GM66150 series

are stable with the 10µF minimum capacitor values at full load. Where the regulator is powered from a

source with a high AC impedance, a 0.1µF capacitor connected between Input and GND is recommended.

This capacitor should have good characteristics to above 250kHz.

14

Share Link: