onsemi CS5201-1GSTR3

Overview

CS5201-1GSTR3 from onsemi is a 1.0 A adjustable linear regulator with ±1.0% output voltage accuracy over temperature, 1.25 V to 5.5 V programmable output range using two external resistors, and 1.0 V typical dropout at full load. It serves as a post-regulator or microprocessor supply in low-voltage, high-transient-response applications.

For engineers reviewing the CS5201-1GSTR3 datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage at 1.0 A, thermal shutdown threshold (150–210°C), load regulation (≤0.40%), ripple rejection (80 dB at 120 Hz), and SOT-223 package compatibility with board space-constrained designs.

Technical Context

The CS5201-1GSTR3 uses a composite PNP-NPN pass transistor architecture enabling stable operation with tantalum output capacitors (≥22 µF) and low ESR requirements. Its error amplifier maintains a precise 1.254 V reference between VOUT and ADJ pins, with adjust pin current of 50 µA (typical) contributing to output voltage error in precision resistor-divider designs.

Thermal shutdown activates at 150°C (min) with 25°C hysteresis, and current limiting begins at 1.1 A (min) under VIN−VOUT = 3.0 V. The device operates within −40°C to +70°C ambient, with junction temperature limited to 150°C and maximum input-to-output differential of 7.0 V.

Key Specifications

Pinout & Package

The CS5201-1GSTR3 is housed in a SOT-223 package (Case 318E), with exposed tab electrically connected to VOUT for thermal conduction and PCB copper pour integration.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar adjustable LDO regulator applications.

Compared with LT1086CM-3.3#PBF and TPS7A4701RGWR, the CS5201-1GSTR3 uniquely balances adjustability, SOT-223 compactness, and robust thermal protection - making it optimal for cost-sensitive industrial controls where voltage flexibility and proven reliability outweigh ultra-low IQ or MHz-range PSRR.

Availability

CS5201-1GSTR3 is available at Aetrix Electronics and suitable for industrial PLC I/O modules, embedded microcontroller power supplies, FPGA configuration rails, and medical sensor signal conditioning requiring stable component supply and long-term manufacturability.

Supply support for CS5201-1GSTR3 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier focused on energy-efficient innovation for automotive, industrial, cloud, and IoT applications.

The CS5201-1GSTR3 belongs to onsemi's linear regulator product line, designed specifically for post-regulation and microprocessor supply roles where low dropout, fast transient response, and integrated fault protection are essential in space-constrained environments.

FAQ

What is the maximum input-to-output voltage differential allowed for the CS5201-1GSTR3?

The CS5201-1GSTR3 has an absolute maximum supply voltage rating of 7.0 V, meaning VIN − VOUT must not exceed this value at any time. Exceeding 7.0 V risks permanent damage, especially during short-circuit conditions where thermal or current-limit protection may not activate quickly enough. This constraint applies regardless of ambient temperature or load current, and must be enforced by external clamping circuitry in high-input-voltage applications.

Does the CS5201-1GSTR3 require an output capacitor, and what type is recommended?

Yes, the CS5201-1GSTR3 requires an output capacitor for stability, with a minimum value of 22 µF tantalum specified in the datasheet. Aluminum electrolytic capacitors are acceptable but exhibit greater ESR variation at low temperatures. Ceramic capacitors alone are not recommended due to near-zero ESR, which can cause oscillation. For best transient performance, a parallel network of tantalum and ceramic capacitors is advised - placed as close as possible to the VOUT and GND pins of the CS5201-1GSTR3.

How does the adjust pin current affect output voltage accuracy in the CS5201-1GSTR3?

The CS5201-1GSTR3 adjust pin draws 50 µA (typical), which flows through the lower resistor (R2) of the external voltage-divider network. This introduces an error term equal to I_Adj × R2 that adds to the ideal output voltage defined by V_REF × (1 + R1/R2). For example, with R2 = 10 kΩ, the error is ~0.5 V - necessitating either lower R2 values or compensation in the design equation. Precision applications must account for this current to achieve ±1.0% overall accuracy.

Can the CS5201-1GSTR3 be used without a heatsink in a SOT-223 package?

The CS5201-1GSTR3 in SOT-223 has a typical junction-to-ambient thermal resistance (R_JA) of 156°C/W. Without a heatsink or significant PCB copper area, power dissipation above ~0.4 W (e.g., 5 V_IN → 3.3 V_OUT @ 0.24 A) will exceed the 150°C junction limit at 70°C ambient. Thermal compound is not applicable to SOT-223, but a minimum 1-inch² copper pour connected to the VOUT tab is strongly recommended to reduce effective R_JA and enable full 1.0 A operation in typical industrial environments.

Is the CS5201-1GSTR3 pin-compatible with other regulators beyond the LT1086 family?

The CS5201-1GSTR3 is explicitly documented as pin-compatible with the LT1086 family in its datasheet, sharing identical pin 1 (Adj), pin 2 (VOUT), pin 3 (VIN) assignments and SOT-223 mechanical outline. No other pin-compatible families are cited in official onsemi documentation. Substitution with non-LT1086 parts - even those with matching pin count and function labels - requires verification of electrical behavior (e.g., reference voltage, shutdown thresholds, stability criteria), as physical pin alignment does not guarantee functional equivalence for the CS5201-1GSTR3.