STMicroelectronics TSH690ID

Overview

TSH690ID from STMicroelectronics is a wideband RF amplifier IC designed for 40 MHz–1 GHz operation in ISM and cellular front-end stages, featuring 28 dB gain at 450 MHz, +13.5 dBm (20 mW) output power at 3 V, and 50 Ω input/output impedance matching. Its bias-adjustable Class-A/AB/Power-down operation enables dynamic control of linearity, efficiency, and quiescent current in low-power transmitters.

For engineers reviewing the TSH690ID datasheet, TSH690ID pinout, TSH690ID application, or TSH690ID equivalent, key selection criteria include adjustable bias-controlled gain mode, 450 MHz/900 MHz small-signal gain and P1dB performance, SO-8 thermal dissipation limits (R_th(j-a) = 140–180 °C/W), and open-collector output requiring external inductive load for impedance matching and harmonic suppression.

Technical Context

The TSH690ID implements a two-stage bipolar RF amplifier architecture with internal 50 Ω matching across 300–1000 MHz. Its open-collector output stage requires external inductive load (e.g., L2 = 56 nH at 450 MHz) to establish DC bias and optimize S22 return loss and harmonic content.

Bias control via Pin 8 (V_bias) directly sets collector current and amplification class: tied to V_CC for linear Class-A operation, reduced voltage for efficient Class-AB, or grounded for zero-current Power-down mode-enabling fast turn-on (~200 µs) ASK modulation in remote control transmitters.

Key Specifications

Pinout & Package

Package: SO-8 plastic micropackage (8-pin small outline), 4.8–5.0 mm × 5.8–6.2 mm body, 1.27 mm pitch, R_th(j-a) = 140–180 °C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar wideband RF amplifier applications.

Compared with MAX2641 and QPL9057, the TSH690ID uniquely combines analog bias-controlled amplification class, sub-3 V operation, and integrated oscillator interface (Pins 5/7), making it optimal for cost-sensitive, battery-powered ISM transmitters requiring OOK modulation and thermal efficiency in SO-8.

Availability

TSH690ID is available at Aetrix Electronics and suitable for 433 MHz ISM transmitters, 868 MHz telemetering systems, and cordless telephone RF stages requiring stable component supply, consistent SO-8 thermal performance, and long-term lifecycle availability.

Supply support for TSH690ID 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in analog, power, and RF solutions for industrial, automotive, and consumer markets.

The TSH690ID belongs to ST's legacy RF amplifier product line, engineered specifically for low-voltage, wideband ISM-band transmitters requiring integrated oscillator capability, analog bias control, and SO-8 thermal reliability.

FAQ

What is the recommended inductor value for L2 at 450 MHz?

For 450 MHz operation, STMicroelectronics specifies L2 = 56 nH to achieve an output return loss of −19 dB. This value optimizes S22 while maintaining +13.5 dBm output power at 3 V. The inductor connects between Pin 4 (V_CC2) and the RF output node (Pin 4 side of L2), forming the collector load for the second transistor stage.

Can the TSH690ID operate without external matching components?

Yes, within 300–1000 MHz, the TSH690ID provides internally matched 50 Ω input and output impedance (S11/S22 < −10 dB). However, external DC blocking capacitors (C1/C2) and supply decoupling (1 nF + 100 pF) are mandatory. The open-collector output still requires an external inductor (L2) for biasing and optimal harmonic performance.

How does V_bias affect harmonic distortion in ASK mode?

At V_bias = V_CC, the device operates in Class-A with lowest distortion (<−30 dBc 2nd harmonic); reducing V_bias shifts to Class-AB, increasing 2nd/3rd harmonics (e.g., −18 dBc/−27 dBc at 450 MHz). For ASK, grounding V_bias stops oscillation entirely, eliminating harmonics during standby.

Is the TSH690ID suitable for 2.4 GHz applications?

No. The TSH690ID is characterized and guaranteed only up to 1000 MHz. At 2.4 GHz, gain drops below 10 dB and output power falls below +5 dBm, with degraded S11/S22 matching. ST does not specify or guarantee performance beyond 1 GHz; use dedicated 2.4 GHz amplifiers such as the TQM7M9006 instead.