Microchip Technology TC1303A-RI1EMF

Overview

TC1303A-RI1EMF 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%+ efficiency at 2.0 MHz switching frequency, 65 µA typical quiescent current, and operates across –40°C to +125°C junction temperature. It is used in portable medical instruments requiring tightly regulated core and bias rails.

For engineers reviewing the TC1303A-RI1EMF datasheet, TC1303A-RI1EMF pinout, TC1303A-RI1EMF application, or TC1303A-RI1EMF equivalent, key selection criteria include buck/LDO output voltage configuration, PG monitoring scope (buck-only), shutdown independence, thermal performance in DFN package, and compatibility with 1 µF LDO output capacitance.

Technical Context

The TC1303A-RI1EMF implements a fixed-frequency PWM buck stage (2.0 MHz) with automatic transition to PFM mode under light load to maintain ultra-low IQ, while its LDO stage uses internal compensation and achieves 137 mV dropout at 200 mA. The power-good signal is an open-drain output tied exclusively to VOUT1 regulation with 300 ms delay, enabling processor reset sequencing.

Its dual independent shutdown inputs (SHDN1 for buck, SHDN2 for LDO) allow flexible power sequencing control, and both regulators feature overtemperature, UVLO, and short-circuit protection. The device requires no external compensation components for either output due to internal compensation.

Key Specifications

Pinout & Package

TC1303A-RI1EMF is housed in a thermally enhanced 10-pin 3×3 mm DFN package with exposed pad (EP) connected to AGND. The package supports high-power-density layouts and provides θJA = 41°C/W on a 4-layer board with thermal vias.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TC1303B-RI1EMF, TC1303A-RI1EMF provides earlier fault detection for processor core supplies; compared with TPS65023RGZR, it offers smaller footprint and lower quiescent current at the cost of one fewer output rail.

Availability

TC1303A-RI1EMF is available at Aetrix Electronics and suitable for portable medical instruments, USB-powered diagnostic tools, and industrial handheld terminals requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for TC1303A-RI1EMF 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 U.S.-based semiconductor manufacturer specializing in microcontrollers, analog devices, and power management ICs for industrial, automotive, and consumer applications.

The TC1303 family was designed to deliver highly integrated, low-quiescent-current dual-rail power solutions for space-constrained portable electronics - prioritizing efficiency, thermal robustness, and ease of layout.

FAQ

What output voltages does the TC1303A-RI1EMF support?

The TC1303A-RI1EMF supports adjustable buck output (0.8 V to 4.5 V) via external resistor divider on VFB1, and fixed LDO outputs including 1.5 V, 1.8 V, 2.5 V, and 3.3 V. The specific output configuration for TC1303A-RI1EMF is factory-set and indicated by the suffix "RI1" - confirming 1.8 V buck and 3.3 V LDO outputs per Microchip's standard ordering matrix.

How does the power-good (PG) function operate on the TC1303A-RI1EMF?

The TC1303A-RI1EMF features an open-drain PG output that monitors only the buck regulator output (VOUT1). It asserts low when VOUT1 falls below 92% of target and releases high when VOUT1 rises above 94%, with built-in 300 ms delay to prevent false resets. This behavior is fixed for the TC1303A variant and cannot be reconfigured - unlike TC1303B (LDO-monitored) or TC1303C (dual-monitored).

Can the TC1303A-RI1EMF be used with ceramic output capacitors?

Yes - the TC1303A-RI1EMF is fully compatible with ceramic capacitors. Its LDO output requires only a 1 µF ceramic capacitor on VOUT2, and the buck output is optimized for 4.7 µF ceramic output capacitance. Internal compensation eliminates ESR requirements, enabling use of low-ESR MLCCs without stability risk.

What is the thermal performance of the TC1303A-RI1EMF in its DFN package?

The TC1303A-RI1EMF in the 10-pin 3×3 mm DFN package achieves θJA = 41°C/W on a standard 4-layer PCB with internal ground plane and thermal vias to the exposed pad. At 500 mA buck load and 300 mA LDO load with 3.6 V input, junction temperature rise remains below 45°C - well within the –40°C to +125°C operating range, even in sealed enclosures.

Does the TC1303A-RI1EMF support independent enable control of both regulators?

Yes - the TC1303A-RI1EMF provides two dedicated enable inputs: SHDN1 controls the 500 mA buck regulator, and SHDN2 controls the 300 mA LDO. Both are active-high logic inputs with thresholds defined as >45% VIN (high) and <15% VIN (low). This allows precise sequencing, partial power-down, or fault-isolation scenarios without external logic.