Microchip Technology TC1303B-SA0EMF

Overview

TC1303B-SA0EMF 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 from 2.7–5.5 V input across –40°C to +125°C. It targets portable battery-powered systems requiring sequenced dual-rail supplies.

For engineers reviewing the TC1303B-SA0EMF datasheet, TC1303B-SA0EMF pinout, TC1303B-SA0EMF application, or TC1303B-SA0EMF equivalent, key selection criteria include LDO-monitored PG behavior, independent shutdown control (SHDN1/SHDN2), 2.0 MHz fixed-frequency PWM operation with automatic PFM transition, internal compensation, and DFN/MSOP package compatibility for space-constrained designs.

Technical Context

The TC1303B-SA0EMF implements a synchronous buck stage switching at 2.0 MHz (1.6–2.4 MHz range) with integrated P-channel and N-channel MOSFETs (R_DS(on) ≈ 450 mΩ each), enabling >90% efficiency under heavy load and seamless transition to low-quiescent-current PFM mode at light loads. Its LDO stage features 25 ppm/°C temperature coefficient and 62 dB PSRR ≤100 Hz.

Power-good logic is configured as a push-pull output (unlike open-drain in TC1303A/C/TC1304) with 94% VOUT2 threshold high, 89% low, and 2% hysteresis - providing deterministic reset signaling for processors dependent on stable auxiliary rail voltage. UVLO activates at 2.55 V (typical) with 200 mV hysteresis.

Key Specifications

Pinout & Package

TC1303B-SA0EMF is available in a 10-lead 3×3 mm DFN package with exposed thermal pad (EP), pin-compatible with the MSOP variant. The DFN offers lower thermal resistance (θ_JA = 41°C/W) versus MSOP (113°C/W), critical for sustained 500 mA buck operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TC1303A-SA0EMF and TPS65023RGZR, TC1303B-SA0EMF uniquely provides LDO-monitored push-pull PG in a minimal 10-pin DFN - simplifying reset circuitry and reducing component count where auxiliary rail stability is the critical boot condition.

Availability

TC1303B-SA0EMF is available at Aetrix Electronics and suitable for portable medical sensors, USB-powered test equipment, and industrial handheld terminals requiring stable component supply with guaranteed long-term manufacturability.

Supply support for TC1303B-SA0EMF 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 components, and power management ICs, headquartered in Chandler, Arizona.

The TC1303 family was designed specifically for space- and power-constrained portable electronics, delivering highly integrated dual-rail regulation with minimal external components and industry-leading quiescent current.

FAQ

What is the power-good (PG) monitoring behavior of TC1303B-SA0EMF?

The TC1303B-SA0EMF monitors only the LDO output (VOUT2) for power-good assertion. Its PG pin is a push-pull output that goes high when VOUT2 reaches 94% of its nominal value and remains high until VOUT2 falls below 89%. This behavior is specific to the TC1303B variant and differs from TC1303A (buck-monitored) and TC1303C/TC1304 (dual-monitored). The TC1303B-SA0EMF PG delay is fixed at 300 ms, aligning with standard processor reset timing requirements.

Can TC1303B-SA0EMF generate adjustable buck output voltages?

Yes, TC1303B-SA0EMF 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%), and the device is internally compensated - no external compensation components are required. Fixed-output versions (e.g., 1.2 V, 1.5 V, 1.8 V, 2.5 V, 3.3 V) are also available, but TC1303B-SA0EMF specifically uses the adjustable configuration per its part number suffix.

What package type does TC1303B-SA0EMF use, and how is thermal performance characterized?

TC1303B-SA0EMF is packaged in a 10-lead 3×3 mm DFN with exposed thermal pad (EP). Its thermal resistance is θ_JA = 41°C/W on a typical 4-layer PCB with internal ground plane and two vias under the EP. This enables continuous 500 mA buck operation up to +85°C ambient without derating, provided proper PCB copper pour and via placement are implemented. The DFN footprint is pin-compatible with the 10-lead MSOP variant, though MSOP has higher θ_JA (113°C/W).

How does TC1303B-SA0EMF manage efficiency across load conditions?

TC1303B-SA0EMF uses automatic transition between PWM and PFM modes: it operates in fixed-frequency 2.0 MHz PWM mode above ~50 mA load for low-noise, predictable regulation, then seamlessly shifts to variable-frequency PFM mode below that threshold to maintain high efficiency (<85%) down to 1 mA. Total quiescent current remains at 65 µA typical across this transition, minimizing battery drain in sleep states. The TC1303B-SA0EMF achieves >90% peak efficiency at 500 mA with 3.6 V input and 1.8 V output.

What protection features are integrated into TC1303B-SA0EMF?

TC1303B-SA0EMF integrates undervoltage lockout (UVLO) activating at 2.55 V (typical) with 200 mV hysteresis, overtemperature shutdown at 165°C (10°C hysteresis), and output short-circuit protection limiting LDO average current to 240 mA. The buck stage includes cycle-by-cycle current limiting and thermal foldback. All protections are fully autonomous - no external components or host intervention required. These safeguards ensure robust operation in unattended portable and industrial deployments where TC1303B-SA0EMF is deployed.