CS8127

 Externally Set Delay for Reset
60V Peak Transient Capability
 Internal Thermal Overload Protection
 3% Output Accuracy
 ActiveRESET
 Noise Immunity
 On Chip EMC Hardening Protection Incorporated
 Externally Set Current Limit

Power Dissipation....................................................................Internally Limited
Input Voltage ....................................................................................-0.3V, 26V
Transient Input Voltage ................................................................................60V
Output Current .......................................................................Externally Limited
ESD Susceptibility (Human Body Model).........................................................2kV
Junction Temperature .................................................................-45 to 150
Storage Temperature..................................................................-55 to 150
Lead Temperature Soldering
    Wave Solder (through hole styles only) ...................10 sec. max, 260 peak
Reflow (SMD styles only) .........................60 sec. max above 183, 230 peak

The CS8127 contains all the necessary control circuitry to implement a 5V linear regulator. An external pass device is used to produce superior performance compared to conventional monolithic regulators. The CS8127 with a TIP42 PNP transistor typically provides a 100mV dropout voltage at 500mA, increasing to 350mV at 3A. Quiescent current at 500mA is only 5mA. Monolithic regulators cannot approach these figures because their power transistors do not provide the high beta and excellent saturation characteristics at high currents. The CS8127 is compatible with a wide variety of external transistors, allowing flexibility for thermal, space, and cost management.

The CS8127 includes thermal shutdown, externally programmable current limit, and over-voltage shutdown, making it suitable for use in automotive and switching regulator post regulator applications. An optional external RC filter added to the CS8127 supply lead provides EMC hardening in addition to the on-chip EMC hardening. The SENSE lead allows remote sensing of the output voltage for improved regulation.

An active microprocessor RESET function is included on-chip with externally programmable delay time. During
power-up, or after detection of any error in the regulated output, the RESET lead will remain in the low state for the duration of the delay. Types of errors include short circuit, low input voltage, overvoltage shutdown, thermal shutdown, or others that cause the output to become unregulated. This function is independent of the input voltage and will function correctly with an output voltage as low as 1V. Hysteresis is included in both the reset and delay comparators for noise immunity and to prevent oscillations. A latching discharge CS8127 is used to discharge the delay capacitor, even when triggered by a relatively short fault condition. This circuit improves upon the commonly used SCR structure by providing improved noise immunity and full capacitor discharge (0.2V typ).