Microchip Technology TC1303B-ZG0EMF

Overview

TC1303B-ZG0EMF 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 94% typical regulation accuracy, 137 mV dropout at 200 mA for VOUT2, and operates across -40°C to +125°C junction temperature. It serves as a compact, low-noise dual-rail supply in portable medical instruments and USB-powered devices.

For engineers reviewing the TC1303B-ZG0EMF datasheet, TC1303B-ZG0EMF pinout, TC1303B-ZG0EMF application, or TC1303B-ZG0EMF equivalent, key selection criteria include its LDO-monitored PG function, independent shutdown control for each regulator, 2.0 MHz fixed-frequency PWM operation under heavy load, automatic PWM-to-PFM transition for ultra-low quiescent current (65 µA typical), and compatibility with 1 µF ceramic output capacitors on both rails.

Technical Context

The TC1303B-ZG0EMF implements a synchronous buck stage with integrated P- and N-channel MOSFETs (R_DS(on) = 450 mΩ each), fixed 2.0 MHz switching frequency, and internal compensation - eliminating external loop components. Its LDO stage uses a separate input (VIN2) and provides stable 300 mA output with <±0.3% voltage tolerance and 25 ppm/°C temperature coefficient.

Power sequencing is managed via two independent logic-controlled shutdown inputs (SHDN1 for buck, SHDN2 for LDO), and the push-pull PG output asserts high when VOUT2 reaches ≥94% of nominal value, with 300 ms delay used for processor reset timing. UVLO (2.55 V typical) and thermal shutdown (165°C) provide system-level protection.

Key Specifications

Pinout & Package

TC1303B-ZG0EMF is housed in a 10-pin 3×3 mm DFN package with exposed thermal pad (EP), pin-compatible with MSOP-10. The EP must be soldered to AGND for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TC1303C-ZG0EMF and TPS650350RGER, TC1303B-ZG0EMF delivers the lowest BOM cost and smallest footprint for applications requiring LDO-only power-good assertion and independent shutdown - ideal for portable instrumentation where simplicity and battery life are prioritized over configurability.

Availability

TC1303B-ZG0EMF is available at Aetrix Electronics and suitable for portable medical instruments, USB-powered test equipment, and industrial handheld terminals requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for TC1303B-ZG0EMF 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, and power management solutions for industrial, automotive, and consumer markets.

The TC1303 family was designed specifically for space-constrained, battery-powered applications requiring dual independent regulated rails with minimal external components and ultra-low quiescent current.

FAQ

What is the power-good (PG) behavior of TC1303B-ZG0EMF?

The TC1303B-ZG0EMF features a push-pull PG output that monitors only the LDO output (VOUT2). It asserts high when VOUT2 reaches ≥94% of its nominal voltage and includes a fixed 300 ms delay before activation - this delay is used to ensure stable power-up before releasing a processor reset signal. The TC1303B-ZG0EMF PG output drives high actively, eliminating the need for an external pull-up resistor.

Can TC1303B-ZG0EMF generate adjustable buck output voltages?

Yes, TC1303B-ZG0EMF supports adjustable buck output (VOUT1) from 0.8 V to 4.5 V using an external resistor divider connected to the VFB1/VOUT1 pin. The internal feedback reference is 0.8 V ±2.5%, enabling precise core voltage tuning for low-power MCUs or FPGAs. Fixed-output variants are also available, but TC1303B-ZG0EMF's pinout and internal architecture fully support adjustable configurations.

What is the minimum input voltage required for TC1303B-ZG0EMF to regulate 3.3 V on VOUT2?

For TC1303B-ZG0EMF to regulate 3.3 V on VOUT2 at 200 mA, the minimum input voltage (VIN2) is 3.437 V - calculated as VOUT2 + dropout voltage (3.3 V + 0.137 V). At 300 mA, dropout rises to 205 mV, requiring VIN2 ≥ 3.505 V. This low dropout enables efficient use of single-cell Li-ion (3.0–4.2 V) or USB (4.75–5.25 V) sources without intermediate regulation.

How does TC1303B-ZG0EMF manage efficiency at light loads?

TC1303B-ZG0EMF automatically transitions from fixed-frequency PWM mode to pulse-frequency modulation (PFM) mode when buck load drops below ~50 mA. This reduces switching losses and lowers total quiescent current to 65 µA typical - critical for battery longevity in always-on applications. The transition is seamless and requires no external control; the LDO stage remains active and contributes ~46 µA independently.

Is TC1303B-ZG0EMF pin-compatible with other TC1303 variants?

Yes, TC1303B-ZG0EMF shares identical 10-pin DFN/MSOP pinout and package dimensions with TC1303A, TC1303C, and TC1304. However, functional differences exist: TC1303B-ZG0EMF has push-pull PG monitoring only VOUT2, while TC1303A uses open-drain PG monitoring VOUT1 and TC1303C monitors both. Pin compatibility enables layout reuse, but firmware and schematic must verify PG behavior and shutdown logic alignment.