MAX8862 查看數據表（PDF） - Maxim Integrated

零件编号

产品描述 (功能)

生产厂家

MAX8862

Low-Cost, Low-Dropout, Dual Linear Regulator

Maxim Integrated 

Low-Cost, Low-Dropout, Dual Linear Regulator

MAX8862

OUT_

SET_

GND

OUTPUT

R1

R2

Figure 2. Adjustable Output Voltage

Reference

The MAX8862 provides a precision 1.25V reference at

REF2. Bypass REF2 with a 0.1µF capacitor to ground.

Larger bypassing capacitors will further reduce the

secondary regulator’s wideband noise.

Shutdown

The MAX8862’s regulators have individual shutdown

controls. A logic low on either SHDN1 or SHDN2 turns

off the corresponding internal reference, error com-

parator, and pass transistors’ control logic, reducing

quiescent current to less than 1µA.

Current Limiting

The MAX8862 features a current limit for each regula-

tor. It monitors and controls the pass transistor’s gate

voltage, limiting the output current to 580mA for the

main regulator and 250mA for the secondary regulator.

The current limits apply to all input and output voltage

conditions. The outputs can be shorted to ground for

an indefinite period of time if the package can dissipate

(VIN1 x ILIM1 + VIN2 x ILIM2) without exceeding TJ =

+150°C (see the Power Dissipation and Operating

Region section).

Thermal Overload Protection

Thermal overload protection limits the MAX8862’s total

power dissipation. When the junction temperature

exceeds TJ = +160°C, the thermal sensor sends a sig-

nal to the shutdown logic, turning off the pass transis-

tors and allowing the device to cool down. The thermal

sensor turns the pass transistors on again after the IC’s

junction temperature decreases by 20°C. If the thermal

overload condition persists, OUT1 and OUT2 pulse on

and off.

Thermal overload protection is designed to protect the

MAX8862 during fault conditions. For continuous oper-

ation, the absolute maximum junction temperature rat-

ing of TJ = +150°C should not be exceeded.

Reverse-Battery Protection

This feature protects the MAX8862 against polarity

reversal at the supply inputs. The inputs can handle

negative voltages up to -12V without suffering any ill

effects. When the input polarity is reversed, the output

will be at the same potential as ground, and no current

will flow from the output back to the input. This feature

protects both the device and the supply-voltage

source. The reverse currents that flow back to the input

are due to RPWROK1 , RSHDN1, and RSHDN2. These

currents are approximately: IREV1 = |VIN1| / (RSHDN1 +

RPWROK1) and IREV2 = |VIN2| / RSHDN2. When operat-

ing the MAX8862 in continuous mode (VSHDN1 = VIN1

and VSHDN2 = VIN2) place a resistor (>20kΩ) between

shutdown and supply inputs to limit the current flow in

case the battery is reversed.

_______________________________________________________________________________________ 9

Share Link: