Microchip Technology TC1303C-ZS0EUN

Overview

TC1303C-ZS0EUN 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 both outputs. It delivers 90% typical efficiency at 2.0 MHz switching frequency, features 65 µA total quiescent current, 137 mV LDO dropout at 200 mA, and operates across –40°C to +125°C for portable medical instruments and USB-powered devices.

For engineers reviewing the TC1303C-ZS0EUN datasheet, TC1303C-ZS0EUN pinout, TC1303C-ZS0EUN application, or TC1303C-ZS0EUN equivalent, key selection criteria include independent shutdown control per rail, dual-output power-good assertion with 300 ms delay, fixed 2.0 MHz PWM-to-PFM transition, and compatibility with 1 µF ceramic output capacitors on the LDO.

Technical Context

The TC1303C-ZS0EUN implements a synchronous buck stage with integrated P- and N-channel MOSFETs (R_DS(on) = 450 mΩ each), fixed 2.0 MHz oscillator, and automatic PWM-to-PFM mode transition under light load to minimize quiescent current. Its LDO stage uses internal compensation and achieves 137 mV dropout at 200 mA with ±0.3% output voltage tolerance.

Power-good logic monitors both VOUT1 and VOUT2 simultaneously with 94% high-threshold and 89% low-threshold hysteresis, 300 ms active timeout period, and open-drain PG output. Undervoltage lockout activates at 2.55 V (typical) with 200 mV hysteresis, and thermal shutdown triggers at 165°C with 10°C hysteresis.

Key Specifications

Pinout & Package

TC1303C-ZS0EUN is housed in a 10-pin 3×3 mm DFN package with exposed thermal pad (EP), optimized for high-density portable PCB layouts. Pin 11 (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 regulator applications.

Compared with MCP1826-3302E/DB and TPS65023RGZR, TC1303C-ZS0EUN delivers verified dual-rail integration in a 10-pin DFN with zero-config power-good monitoring - ideal for cost-sensitive, space-constrained portable designs where simplicity and guaranteed startup timing are critical.

Availability

TC1303C-ZS0EUN is available at Aetrix Electronics and suitable for USB-powered devices, handheld medical instruments, and cellular phone subsystems requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for TC1303C-ZS0EUN 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 industrial, automotive, communications, and consumer markets with high-reliability silicon and development tools.

The TC1303 family was designed specifically for portable electronics requiring ultra-low quiescent current, dual-rail power conversion, and integrated power-good signaling - targeting battery life extension and simplified system reset architecture.

FAQ

What output voltages does TC1303C-ZS0EUN support?

TC1303C-ZS0EUN supports an adjustable buck output from 0.8 V to 4.5 V (via external resistor divider on VFB1) and fixed LDO outputs of 1.5 V, 1.8 V, 2.5 V, or 3.3 V. The specific output configuration for TC1303C-ZS0EUN is factory-set and indicated by the suffix 'ZS0' - confirming 1.8 V buck and 3.3 V LDO outputs. Both rails maintain ±0.3% tolerance over load and temperature.

How does the power-good (PG) function operate in TC1303C-ZS0EUN?

In TC1303C-ZS0EUN, the PG pin is an open-drain output that asserts low only when both VOUT1 and VOUT2 are within 94% to 96% of their nominal values. It incorporates a 300 ms active timeout period and 2% hysteresis to prevent chatter during marginal conditions. This dual-monitoring behavior distinguishes TC1303C-ZS0EUN from TC1303A (buck-only monitoring) and TC1303B (LDO-only monitoring).

Can TC1303C-ZS0EUN operate with a single input source for both VIN1 and VIN2?

Yes - TC1303C-ZS0EUN is explicitly designed for single-input operation: VIN1 and VIN2 are intended to be tied together with short, low-impedance traces. The datasheet specifies that both inputs accept 2.7 V to 5.5 V and must share the same source. This simplifies layout and eliminates need for separate input filtering or sequencing between rails.

What thermal performance can be expected from TC1303C-ZS0EUN in its DFN package?

TC1303C-ZS0EUN in the 10-lead 3×3 mm DFN package has a typical junction-to-ambient thermal resistance (θ_JA) of 41°C/W on a 4-layer PCB with internal ground plane and two thermal vias under the exposed pad. At full 500 mA buck + 300 mA LDO load, this enables operation up to +85°C ambient without derating - validated by Microchip's thermal characterization in DS21949C-page 10.

Is external compensation required for the buck or LDO stages of TC1303C-ZS0EUN?

No - both the synchronous buck regulator and the LDO in TC1303C-ZS0EUN are internally compensated. The buck stage requires only a 4.7 µH inductor and 4.7 µF input/output capacitors; the LDO requires only a single 1 µF ceramic capacitor on VOUT2. This eliminates external compensation networks and reduces design risk associated with stability analysis.