Texas Instruments TPS7133QD

Overview

TPS7133QD from Texas Instruments is a 3.3-V fixed-output micropower low-dropout (LDO) voltage regulator featuring PMOS pass architecture, 2% output voltage tolerance over line/load/temperature, 47 mV dropout at 100 mA, 285 µA typical quiescent current independent of load, and integrated power-good (PG) status output. It delivers up to 500 mA output current and supports battery-powered portable instrumentation requiring stable low-noise supply with sleep-mode capability.

For engineers reviewing the TPS7133QD datasheet, TPS7133QD pinout, TPS7133QD application, or TPS7133QD equivalent, key selection criteria include dropout performance at light-to-full load, PG threshold accuracy for system reset timing, thermal derating in SOIC-8 packages, and compatibility with ceramic output capacitors ≥4.7 µF.

Technical Context

The TPS7133QD uses a PMOS pass transistor instead of conventional PNP, enabling ultra-low dropout voltage directly proportional to output current (V_DO = I_O × r_DS(on)) and eliminating load-dependent quiescent current. Its internal 1.178-V reference feeds a precision error amplifier driving the gate of the PMOS element.

Power-good (PG) logic monitors output voltage via SENSE pin, asserting low when V_OUT drops below 2.868 V (–40°C to 125°C), with 35-mV hysteresis. Enable (EN) input accepts TTL-compatible logic and reduces quiescent current to ≤0.5 µA in shutdown mode.

Key Specifications

Pinout & Package

TPS7133QD is housed in an 8-pin SOIC (D) package with 1.27 mm pitch, 4.9 mm × 3.9 mm footprint, and 1.75 mm maximum height. Thermal resistance θ_JA = 106°C/W enables 464 mW power dissipation at 70°C ambient.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7133QD, TPS7333QD omits PG and trades tolerance for cost, while MCP1703T-3302E/MB achieves nanoamp quiescent current at the expense of missing fault-monitoring capability and thermal headroom - making TPS7133QD optimal for industrial and automotive applications demanding both precision and system-level supervision.

Availability

TPS7133QD is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, handheld test equipment, and automotive body control units requiring stable component supply with guaranteed long-term availability.

Supply support for TPS7133QD 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

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, specializing in analog, embedded processing, and connectivity technologies for industrial, automotive, and consumer markets.

The TPS71xx family was designed specifically for micropower, low-dropout regulation in battery-critical applications, emphasizing ultra-low quiescent current, precise PG monitoring, and robust operation across extended temperature ranges.

FAQ

What is the minimum input voltage required for TPS7133QD to maintain regulated 3.3-V output at 500 mA?

The minimum input voltage is calculated as V_IN(min) = V_OUT + V_DO(max). Per datasheet Section 6, dropout is 300 mV max at 500 mA and 25°C, and 400 mV max at 500 mA over –40°C to 125°C. Thus, TPS7133QD requires ≥3.63 V at room temperature and ≥3.73 V across full temperature range to sustain 3.3 V at full load.

Does TPS7133QD require an external resistor divider for output voltage setting?

No. TPS7133QD is a fixed 3.3-V output variant and does not use the FB pin. Its SENSE pin is internally connected to the output reference and must be tied directly to the OUT pin externally per datasheet Note A - no external resistors are needed or supported.

How is the power-good (PG) output of TPS7133QD configured and used in system design?

PG is an open-drain output that pulls low when V_OUT falls below 2.868 V (–40°C to 125°C). It requires an external pull-up resistor (typically 10–100 kΩ) to a logic-supply rail. In TPS7133QD designs, PG connects to a microcontroller's NMI or dedicated reset input to initiate controlled shutdown or reboot upon undervoltage.

Can TPS7133QD operate with a 4.7-µF ceramic output capacitor, and what is the impact on stability?

Yes. Datasheet Figure 2 and electrical characteristics specify CO = 4.7 µF ceramic (X7R/X5R) with CSR = 1 Ω as the standard test condition. This configuration ensures unconditional stability per TI's compensation design - no additional series resistance or capacitor type restrictions apply for TPS7133QD.

What is the thermal performance limit of TPS7133QD in SOIC-8 (D) package at 70°C ambient?

In SOIC-8 (D) package, TPS7133QD has θ_JA = 106°C/W. At 70°C ambient, maximum allowable power dissipation is 464 mW (per Dissipation Rating Table 1). For a 3.3-V output at 500 mA, input must be ≤4.23 V to stay within this limit - higher input voltages require thermal derating or heatsinking.