Vishay Semiconductor Opto Division TSOP75438WTT

Overview

TSOP75438WTT from Vishay Semiconductors is a surface-mount infrared (IR) receiver module optimized for long-burst remote control systems operating at 38 kHz carrier frequency. It integrates a PIN photodiode, preamplifier, AGC circuit, bandpass filter, and demodulator in a single epoxy package with integrated IR filter. It delivers active-low demodulated output directly compatible with microcontrollers for NEC, Sharp, and Mitsubishi protocol decoding in consumer electronics remotes.

For engineers reviewing the TSOP75438WTT datasheet, TSOP75438WTT pinout, TSOP75438WTT application, or TSOP75438WTT equivalent, key selection criteria include its 38 kHz center frequency, ±75° horizontal directivity, 0.25–0.45 mA supply current at 3.3 V, AGC4 configuration for enhanced noise immunity in LCD/LED lighting environments, and compatibility with standard IR transmitter diodes such as TSAL6200.

Technical Context

The TSOP75438WTT implements a tuned 38 kHz bandpass amplifier with automatic gain control (AGC4 variant), enabling robust suppression of ambient IR interference from fluorescent lamps, Wi-Fi routers, and LCD backlighting. Its internal demodulator outputs a clean, active-low digital signal synchronized to the IR burst envelope without requiring external timing components.

Designed for long-burst protocols, it requires ≥10 cycles/burst and enforces minimum gap times (≥12 cycles after each burst; >15× burst length for continuous streams). Its spectral response peaks at 950 nm with full-width half-maximum spanning ~850–1050 nm, and it achieves up to 18 m transmission distance using TSAL6200 at 50 mA drive current.

Key Specifications

Pinout & Package

TSOP75438WTT uses a 4-pin surface-mount TSOP package (6.8 mm × 3.0 mm × 2.35 mm) with Heimdall no-lens construction and integrated IR filter. The lead frame assembly includes a molded epoxy body and pick-and-place fiducials aligned to JEDEC MS-012 standards.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar IR receiver module applications.

Compared with TSOP75238W, TSOP75438WTT provides superior noise immunity in mixed-lighting environments but trades slight reduction in universal code compatibility; versus TSDP3438, it offers wider angular coverage and SMD assembly compatibility at the expense of peak sensitivity and optical gain.

Availability

TSOP75438WTT is available at Aetrix Electronics and suitable for TV remote controls, set-top box interfaces, audio system remotes, and home appliance IR receivers requiring stable component supply across high-volume consumer electronics production.

Supply support for TSOP75438WTT 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

Vishay Semiconductors is a global leader in discrete semiconductors and passive components, specializing in high-reliability optoelectronics, power management, and sensing solutions for industrial and consumer markets.

The TSOP754..W series belongs to Vishay's IR receiver module product line, engineered specifically for robust long-burst remote control systems in electrically noisy, multi-light-source environments such as modern living rooms with LED/LCD displays and Wi-Fi infrastructure.

FAQ

What is the carrier frequency supported by TSOP75438WTT?

The TSOP75438WTT is factory-tuned to a nominal carrier frequency of 38 kHz, optimized for NEC, Sharp, and Mitsubishi infrared remote control protocols. Its bandpass filter has a 3 dB bandwidth of ±3.8 kHz (f₀/10), ensuring high selectivity against adjacent frequencies like 36 kHz or 40 kHz interference sources. This exact center frequency is laser-trimmed during manufacturing and cannot be adjusted externally.

Does TSOP75438WTT require external components for basic operation?

No, TSOP75438WTT operates autonomously with only a single 100 nF ceramic decoupling capacitor between VS (pin 2) and GND (pins 1 and 4). Its integrated AGC, demodulator, and IR filter eliminate the need for external amplifiers, filters, or timing resistors. The active-low OUT (pin 3) connects directly to a microcontroller GPIO with a standard 4.7 kΩ pull-up resistor.

What is the meaning of "AGC4" in TSOP75438WTT?

"AGC4" denotes the fourth gain-control variant in the TSOP754..W family, configured for maximum noise suppression in long-burst remote control systems. Compared to AGC2 (e.g., TSOP75238W), AGC4 dynamically reduces receiver sensitivity in the presence of strong ambient IR noise-such as from fluorescent lamps-while maintaining accurate burst envelope detection for NEC and Sharp codes. This trade-off slightly reduces compatibility with very short or non-standard bursts.

Is TSOP75438WTT qualified for automotive applications?

No, TSOP75438WTT is explicitly not qualified to AEC-Q200 or other automotive reliability standards. Vishay documentation states these devices "have not been qualified to automotive specifications" and specifies an operating temperature range of −25 °C to +85 °C-below the extended −40 °C to +105 °C requirement for under-hood or dashboard automotive use. It is intended solely for consumer and industrial indoor applications.

How does TSOP75438WTT handle interference from fluorescent lighting?

TSOP75438WTT suppresses interference from both low- and high-modulation fluorescent lamps (per Figures 14 and 15 in the datasheet) via its AGC4-controlled dynamic threshold adjustment and burst-length validation logic. When ambient IR noise exceeds detection thresholds, the AGC reduces gain to prevent false triggering, while the internal timing circuit rejects continuous or irregularly modulated signals that fail minimum burst length (≥10 cycles) and inter-burst gap requirements.