Microchip Technology TC1303B-ZA0EMF

Overview

TC1303B-ZA0EMF 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 the power-good (PG) output monitoring only the LDO output (VOUT2). It delivers 1.8 V on VOUT1 and 3.3 V on VOUT2, operates from 2.7–5.5 V input, achieves >90% efficiency at heavy load, and features 65 µA typical quiescent current. It targets portable battery-powered systems requiring tightly regulated dual rails.

For engineers reviewing the TC1303B-ZA0EMF datasheet, TC1303B-ZA0EMF pinout, TC1303B-ZA0EMF application, or TC1303B-ZA0EMF equivalent, key selection criteria include LDO-monitored PG behavior, independent SHDN1/SHDN2 control, 2.0 MHz fixed-frequency PWM operation, 137 mV typical dropout at 200 mA for VOUT2, and DFN-10 package compatibility with thermal pad grounding.

Technical Context

The TC1303B-ZA0EMF implements a synchronous buck converter with PFM/PWM auto-transition and an internally compensated LDO - both outputs are independently shutdown via dedicated logic inputs (SHDN1 and SHDN2). Its PG output is push-pull and asserts only when VOUT2 reaches ≥94% of nominal, with 300 ms delay used for processor reset sequencing.

It uses a fixed 2.0 MHz switching frequency under heavy load, supports adjustable (0.8–4.5 V) or standard fixed VOUT1 voltages, and offers standard fixed VOUT2 options including 1.5 V, 1.8 V, 2.5 V, and 3.3 V. The device integrates UVLO (2.55 V typ), overtemperature protection (165 °C), and short-circuit protection on both outputs.

Key Specifications

Pinout & Package

TC1303B-ZA0EMF is housed in a thermally enhanced 10-pin 3×3 mm DFN package with exposed thermal pad (EP), requiring connection to AGND for optimal thermal performance and noise immunity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TC1303A-ZA0EMF and TC1303C-ZA0EMF, the TC1303B-ZA0EMF uniquely provides LDO-only PG monitoring with push-pull drive - offering simplified reset integration for designs where I/O rail readiness determines system boot readiness, without requiring external pull-up components or dual-rail coordination logic.

Availability

TC1303B-ZA0EMF is available at Aetrix Electronics and suitable for cellular phones, portable computers, and USB-powered devices requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for TC1303B-ZA0EMF 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 microcontroller, mixed-signal, analog, and Flash-IP solutions, serving automotive, industrial, consumer, and communications markets with high-reliability semiconductor products.

The TC1303 family is designed for space-constrained, battery-operated portable electronics requiring highly integrated dual-rail power management with minimal external components and robust protection features.

FAQ

What output voltages does the TC1303B-ZA0EMF provide?

The TC1303B-ZA0EMF provides fixed 1.8 V on its buck output (VOUT1) and fixed 3.3 V on its LDO output (VOUT2). These values are factory-trimmed and do not require external feedback resistors. The part number suffix "ZA0EMF" specifically denotes this 1.8 V / 3.3 V configuration in the 10-pin DFN package. Both outputs maintain ±0.3% tolerance over temperature and load.

How does the power-good (PG) function work on the TC1303B-ZA0EMF?

The TC1303B-ZA0EMF's PG pin is a push-pull output that asserts high only when the LDO output (VOUT2) reaches and sustains ≥94% of its nominal 3.3 V value, with a built-in 300 ms delay. This behavior is specific to the TC1303B variant. Unlike TC1303A (buck-monitored) or TC1303C (dual-monitored), the TC1303B-ZA0EMF uses PG exclusively for LDO regulation confirmation - ideal for systems where I/O rail readiness triggers boot.

Can the TC1303B-ZA0EMF operate from a single 3.7 V Li-ion battery?

Yes, the TC1303B-ZA0EMF supports input voltages from 2.7 V to 5.5 V, making it fully compatible with a single-cell Li-ion battery (nominal 3.7 V, discharge range ~3.0–4.2 V). At 3.6 V input, it delivers 1.8 V @ 500 mA and 3.3 V @ 300 mA with >90% efficiency on the buck stage and 137 mV dropout on the LDO - ensuring stable dual-rail operation across the full battery discharge curve.

What is the thermal performance of the TC1303B-ZA0EMF in its DFN package?

The TC1303B-ZA0EMF in the 3×3 mm 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. When properly soldered with the EP connected to AGND, it sustains continuous 500 mA buck and 300 mA LDO output currents at ambient temperatures up to +85°C without thermal shutdown - verified per its −40°C to +125°C junction rating.

Does the TC1303B-ZA0EMF require external compensation components?

No, the TC1303B-ZA0EMF features internally compensated control loops for both the buck regulator and the LDO - eliminating the need for external compensation capacitors or resistors on either output. This reduces bill-of-materials cost and PCB area, and ensures stable operation with only the required input/output capacitors (4.7 µF on VIN, 1 µF on VOUT2) and 4.7 µH inductor on the buck stage.