Texas Instruments TPS65148RHBT

Overview

TPS65148RHBT from Texas Instruments is a compact TFT LCD bias IC integrating a 18 V/4 A boost converter, 12.5 V ±0.5% LDO for gamma buffer (VREG_O), unity-gain VCOM buffer (±130 mA), gate voltage shaping (VGHM), and active LCD discharge/reset (XAO). It operates from 2.5–6 V input and targets 5 V-input monitor power systems.

For engineers reviewing the TPS65148RHBT datasheet, TPS65148RHBT pinout, TPS65148RHBT application, or TPS65148RHBT equivalent, key selection criteria include its dual-frequency (630 kHz / 1.2 MHz) boost architecture, integrated VGHM discharge control via RE/VFLK, OVP-triggered latch-down behavior, and QFN-32 thermal performance (θ_JA = 37.1°C/W).

Technical Context

The TPS65148RHBT implements a current-mode boost converter with adaptive off-time control, selectable 630 kHz or 1.2 MHz switching, and internal 4 A N-channel MOSFET switch (r_DS(on) ≤ 0.18 Ω). Its VCOM buffer delivers ±130 mA output current with 60 MHz bandwidth and 66 dB CMRR, while the VGHM gate shaping block uses two PMOS switches (r_DS(on) ≤ 25 Ω each) controlled by VFLK logic and RE-slope resistor.

Reset function (XAO) provides open-drain active-low signal with 1.240 V threshold (±24 mV), 65 mV hysteresis, and 1 mA sink capability; LCD discharge is synchronized to XAO assertion and VFLK-driven VGHM ramp-down. Safety features include overvoltage protection (19 V trip on SUP), thermal shutdown (150°C), and short-circuit protection via external isolation switch driven by GD pin.

Key Specifications

Pinout & Package

TPS65148RHBT uses a 32-pin QFN package (5 mm × 5 mm, 0.5 mm pitch) with exposed thermal pad (PowerPAD®) for enhanced thermal dissipation. Pin numbering follows standard counter-clockwise layout starting from top-left corner (Pin 1 = REG_FB).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LCD bias applications.

Compared with TPS65148RHBT, TPS65136RHBR omits VCOM buffering and XAO discharge-increasing external component count-while MAX1627EAP+ lacks VGHM control and delivers only half the VCOM current, limiting panel scalability and power-off reliability.

Availability

TPS65148RHBT is available at Aetrix Electronics and suitable for monitor power supplies, TV panel bias systems, industrial HMIs, and medical imaging displays requiring stable component supply and long-term manufacturability.

Supply support for TPS65148RHBT 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 ICs, with decades of expertise in display power solutions.

The TPS65148RHBT belongs to TI's LCD bias IC product line, engineered specifically for compact, high-integration TFT panel power architectures in 5 V-input monitors and TVs.

FAQ

What is the maximum output current capability of the TPS65148RHBT boost converter?

The TPS65148RHBT boost converter supports up to 500 mA continuous output current at 13.6 V with 630 kHz switching and proper inductor selection (e.g., CDRH127NP-100N). Peak switch current is limited to 4.0–5.6 A, enabling robust operation under transient loads. The actual deliverable current depends on input voltage, output voltage, and thermal design-efficiency drops above 400 mA at 18 V output in 1.2 MHz mode.

How does the TPS65148RHBT implement LCD discharge during power-off?

The TPS65148RHBT coordinates LCD discharge using two integrated functions: the XAO pin asserts an active-low reset signal, while the VFLK input triggers VGHM discharge through the RE-connected resistor. When VFLK goes low, the internal M2 PMOS (r_DS(on) ≤ 25 Ω) discharges VGHM to ground, collapsing gate voltage and enabling pixel charge bleed-off. This sequence is synchronized to XAO assertion for reliable black-state transition.

Can the TPS65148RHBT's VCOM buffer drive large-panel capacitance?

Yes-the TPS65148RHBT VCOM buffer delivers ±130 mA output current with 60 MHz bandwidth and 60 V/ms slew rate, enabling full-scale settling within microseconds for panel capacitances up to 15 µF. Its 66 dB CMRR and 15 mV input offset ensure stable DC backplane voltage even under noisy supply conditions, making it suitable for 24-inch+ monitors and diagnostic-grade displays.

What happens if the FB pin is shorted to ground on the TPS65148RHBT?

If the FB pin is shorted to ground, the TPS65148RHBT's overvoltage protection activates: the SUP pin voltage rises unchecked until the OVP comparator trips at ~19 V, disabling the boost switch. If FB remains low for >55 ms, the device latches down and requires a full VIN cycle to recover. XAO remains functional during this fault, allowing external systems to detect failure via its open-drain state.

Does the TPS65148RHBT support both 630 kHz and 1.2 MHz switching simultaneously?

No-the TPS65148RHBT supports only one switching frequency at a time, selected by the FREQ pin: logic low (GND) configures 630 kHz, logic high (VIN) selects 1.2 MHz. The choice trades off light-load efficiency (better at 630 kHz) versus output ripple and transient response (superior at 1.2 MHz). Both modes use the same internal compensation network and require matching inductor values per TI's design guidelines.