Microchip Technology TC1303A-ZI0EUNTR

Overview

TC1303A-ZI0EUNTR from Microchip Technology is a dual-output power management IC integrating a 500 mA synchronous buck regulator and a 300 mA low-dropout linear regulator (LDO), with power-good monitoring of the buck output only. It delivers 90% typical efficiency at 2.0 MHz switching frequency, features 65 µA total quiescent current, and supports adjustable (0.8–4.5 V) or fixed buck outputs (e.g., 1.2 V, 1.5 V, 1.8 V). It is designed for space-constrained portable electronics requiring tightly regulated dual-rail supplies.

For engineers reviewing the TC1303A-ZI0EUNTR datasheet, TC1303A-ZI0EUNTR pinout, TC1303A-ZI0EUNTR application, or TC1303A-ZI0EUNTR equivalent, key selection criteria include buck/LDO output independence, 300 ms PG delay for processor reset, UVLO (2.55 V typ), thermal/short-circuit protection, and compatibility with 1 µF LDO output capacitance.

Technical Context

The TC1303A-ZI0EUNTR implements a fixed-frequency 2.0 MHz PWM buck stage with automatic transition to PFM mode under light load to minimize IQ, while the LDO operates independently with 137 mV dropout at 200 mA. Its power-good circuit monitors only the buck output (VOUT1), asserting an open-drain PG signal after a 300 ms delay once regulation is achieved.

Internal compensation eliminates external loop components for both regulators. Shutdown control is split: SHDN1 disables the buck regulator, SHDN2 disables the LDO - enabling flexible sequencing in battery-powered systems without external logic.

Key Specifications

Pinout & Package

TC1303A-ZI0EUNTR is housed in a 10-pin 3×3 mm DFN package with exposed thermal pad (EP), optimized for high-power-density portable designs. Pin numbering follows standard DFN orientation (pin 1 top-left, counterclockwise).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-output regulator applications.

Compared with MCP16311-H/MS and TPS65023RSBR, TC1303A-ZI0EUNTR offers the smallest footprint (3×3 mm DFN) and lowest quiescent current (65 µA) for fixed dual-rail applications where programmability and extra outputs are unnecessary.

Availability

TC1303A-ZI0EUNTR is available at Aetrix Electronics and suitable for cellular phones, portable medical instruments, and USB-powered embedded devices requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TC1303A-ZI0EUNTR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology is a leading provider of microcontrollers, analog, and Flash-IP solutions, serving automotive, industrial, and consumer markets with high-reliability semiconductor products.

TC1303A-ZI0EUNTR belongs to Microchip's TC1303 series of dual-output power management ICs, engineered specifically for cost-sensitive, space-constrained portable electronics requiring efficient, sequenced dual-rail generation without external supervision.

FAQ

What output voltages does TC1303A-ZI0EUNTR support for its buck and LDO stages?

TC1303A-ZI0EUNTR supports adjustable buck output from 0.8 V to 4.5 V (via external resistor divider on VFB1) or factory-fixed options including 0.8 V, 1.2 V, 1.5 V, 1.8 V, 2.5 V, and 3.3 V. The LDO output is fixed at 1.5 V, 1.8 V, 2.5 V, or 3.3 V - the "ZI0EUNTR" suffix indicates a 1.2 V buck / 3.3 V LDO configuration. Both outputs maintain ±0.3% tolerance across –40°C to +85°C ambient.

How does the power-good (PG) function operate in TC1303A-ZI0EUNTR?

In TC1303A-ZI0EUNTR, the PG pin is an open-drain output that monitors only the buck regulator output (VOUT1). It asserts low when VOUT1 reaches ≥94% of its nominal value and remains asserted for ≥300 ms after regulation is achieved. The PG signal releases processor reset lines per JEDEC JESD22-A102; it deasserts within 165 µs if VOUT1 drops below 92% of target.

Can TC1303A-ZI0EUNTR operate with a single input source for both VIN1 and VIN2?

Yes - TC1303A-ZI0EUNTR is designed for shared-input operation: VIN1 and VIN2 must be connected together with short, low-inductance traces. The datasheet specifies this configuration (Note 8), and electrical characteristics assume identical 2.7–5.5 V supply on both pins. This simplifies power tree design while maintaining independent regulation and shutdown control for each output.

What thermal performance can be expected from TC1303A-ZI0EUNTR in a 3×3 mm DFN package?

TC1303A-ZI0EUNTR in its 10-pin DFN package has a typical junction-to-ambient thermal resistance (θJA) of 41°C/W on a 4-layer PCB with internal ground plane and two vias under the exposed pad. At full 500 mA buck + 300 mA LDO load, junction temperature rise is ~33°C above ambient - well within the –40°C to +125°C operating range. Thermal shutdown activates at +165°C with 10°C hysteresis.

Does TC1303A-ZI0EUNTR require external compensation components for stability?

No - TC1303A-ZI0EUNTR features fully internal compensation for both the buck regulator and LDO. Neither output requires external compensation capacitors or resistors. Stability is guaranteed with minimum 4.7 µF input capacitance and 4.7 µF (buck) / 1 µF (LDO) ceramic output capacitors, as verified across all operating conditions in Microchip's DS21949C characterization.