MC33997

Freescale Semiconductor, Inc. MOTOROLA SEMICONDUCTOR TECHNICAL DATA Document order number: MC33997/D Rev 3.0, 03/2003 Advance Information Switching Power Supply with Linear Regulators The 33997 is a medium-power, multi-output power supply integrated circuit that is capable of operating over a wide input voltage range, from 6.0 V up to 26.5 V with 40 V transient capability. It incorporates a sensorless current mode control step-down switching controller regulating directly to 5.0 V. The 3.3 V linear regulator uses an external pass transistor to reduce the 33997 power dissipation. The 33997 also provides a 3.3 V linear standby regulator and two 5.0 V sensor supply outputs protected by internal low-resistance LDMOS transistors. There are two separate enable pins for the main and sensor supply outputs and standard supervisory functions such as resets with power-up reset delay. The 33997 provides proper power supply sequencing for advanced microprocessor architectures such as the Motorola MPC5xx and 683xx microprocessor families. Features Operating Voltage Range 6.0 V up to 26.5 V (40 V transient) Step-Down Switching Regulator Output VDDH = 5.0 V @ 1400 mA (total) Linear Regulator with External Pass Transistor VDDL = 3.3 V @ 400 mA Low-Power Standby Linear Regulator VKAM = 3.3 V @ 10 mA Two 5.0 V @ 200 mA (typical) Sensor Supplies VREF Protected Against Short-to-Battery and Short-to-Ground with Retry Capability Undervoltage Shutdown on the VDDL, VDDH Outputs with Retr...