Texas Instruments TPS6735IDR

Overview

TPS6735IDR from Texas Instruments is a fixed-frequency, current-mode PWM inverting DC/DC converter delivering −5 V at up to 200 mA from a 4.5–6.2 V input. It integrates a 0.4-Ω p-channel MOSFET power switch, 1.22-V reference output (125 µA capable), soft-start control, and enable shutdown with 1 µA quiescent current. It targets board-level negative rail generation in computer peripherals and battery-powered systems.

For engineers reviewing the TPS6735IDR datasheet, TPS6735IDR pinout, TPS6735IDR application, or TPS6735IDR equivalent, key selection considerations include its inverting topology, SOIC-8 package, −5 V regulated output, 160-kHz fixed switching frequency, and EN-controlled low-power shutdown mode.

Technical Context

The TPS6735IDR implements a current-mode PWM architecture with a 160-kHz oscillator, slope-compensated current sensing, and an internal 1.22-V bandgap reference. Its error amplifier compares FB voltage against REF via external resistor divider to regulate output voltage.

It features undervoltage lockout (UVLO) at 3.7 V, overcurrent protection tripping at 2 A peak switch current, and soft-start initiated by capacitor charging at SS pin. The gate driver uses the −5 V output rail to reduce die area for the integrated PMOS switch.

Key Specifications

Pinout & Package

TPS6735IDR is housed in an 8-pin SOIC (D) package per JEDEC MS-012, tape-and-reel format (2500 pcs/reel), with lead finish NiPdAu and MSL Level-1 rating.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar inverting DC/DC converter applications.

Compared with MAX735CPA+ and LM2662MM/NOPB, the TPS6735IDR delivers higher output current, integrated soft-start, lower shutdown current, and a stable reference - making it optimal for regulated, medium-power inverting applications where efficiency, thermal management, and controlled startup are critical.

Availability

TPS6735IDR is available at Aetrix Electronics and suitable for computer peripherals, battery-powered test equipment, and industrial sensor signal conditioning requiring stable component supply and long-term production continuity.

Supply support for TPS6735IDR 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 leader specializing in analog, embedded processing, and power management technologies with decades of DC/DC converter innovation.

The TPS6735 product line was designed specifically for efficient, compact, inverting DC/DC conversion in space- and power-constrained systems requiring regulated negative voltage rails.

FAQ

What is the maximum output current capability of the TPS6735IDR?

The TPS6735IDR delivers up to 200 mA continuous output current at −5 V under recommended operating conditions (VCC = 4.5–6.2 V, TA = −40°C to 85°C). Peak switch current is limited to 2 A for overcurrent protection. Performance curves show usable load current up to 270 mA at nominal conditions, but 200 mA is the guaranteed specification across full temperature and input voltage range. The TPS6735IDR maintains regulation within ±5% over this load range.

Does the TPS6735IDR require an external Schottky diode, and why?

Yes, the TPS6735IDR requires an external Schottky diode (e.g., 1N5817) connected between OUT and the output capacitor. Because it uses a single p-channel MOSFET in an inverting buck-boost topology, the diode provides the return path for inductor current during the switch-off phase. A Schottky type is specified for its low forward voltage and fast recovery to minimize conduction loss and ripple. The TPS6735IDR datasheet recommends a 1-A rated device for full 200-mA output capability.

Can the TPS6735IDR generate output voltages other than −5 V?

No - the TPS6735IDR is a fixed-output inverting converter optimized exclusively for −5 V. Its internal feedback network and reference are trimmed to regulate precisely at −5 V. Unlike adjustable regulators, it does not support external resistor dividers to set alternate output voltages. For non-standard negative outputs, designers must select a different part such as the TPS6734 (adjustable) or use external scaling circuitry - which compromises regulation accuracy and efficiency. The TPS6735IDR's design centers entirely on stable −5 V generation.

What is the purpose of the SS (soft-start) pin on the TPS6735IDR, and how is it implemented?

The SS pin on the TPS6735IDR controls the soft-start function by accepting an external capacitor to ground. During power-up or EN activation, an internal 1.2-MΩ pull-up charges this capacitor, gradually raising the error amplifier's output clamp voltage and limiting peak switch current on a cycle-by-cycle basis. This prevents output overshoot and inrush current. A minimum 10-nF capacitor is required; typical values range from 10 nF to 1 µF depending on desired startup delay (e.g., 100 nF ≈ 10 ms). The TPS6735IDR also discharges SS during UVLO or overcurrent faults to ensure controlled restart.

Is the TPS6735IDR pin-compatible with the MAX735, and what are the implications?

Yes, the TPS6735IDR is explicitly documented as pin-for-pin compatible with the MAX735 in SOIC-8 (D) and PDIP-8 (P) packages. This allows direct replacement in existing MAX735 layouts without PCB modification. Key functional improvements include lower no-load current (1.9 mA vs. ~2.5 mA), integrated soft-start (absent in MAX735), and tighter output voltage tolerance (±5% vs. ±8%). However, the TPS6735IDR's REF pin provides a 1.22-V output unavailable on the MAX735 - enabling new biasing options without adding external references.