Texas Instruments SN761640DBTR

Overview

SN761640DBTR from Texas Instruments is a digital TV tuner IC integrating a 3-band (VHF-L/VHF-H/UHF) synthesized PLL tuner, mixer, RF AGC detector, and IF gain-controlled amplifier. It delivers 35 dB conversion gain, –95 dBc/Hz phase noise at 10 kHz offset (VHF-L), 66 dB IF gain control range, and supports both analog (AIF OUT) and digital (DIF OUT1/DIF OUT2) IF outputs. It is designed for terrestrial and cable digital TV front-ends.

For engineers reviewing the SN761640DBTR datasheet, SN761640DBTR pinout, SN761640DBTR application, or SN761640DBTR equivalent, key selection considerations include its triple-band oscillator architecture, programmable reference divider (24/28/32/64/80/128), high-voltage VTU output (up to 33 V), four NPN band-switch drivers, and I²C-configurable IF GCA control - all in a 44-pin TSSOP package.

Technical Context

The SN761640DBTR implements a fully integrated PLL-based frequency synthesis architecture with three independent oscillator sections (VLO, VHI, UHF), each with dedicated base/collector pins for external transistor-based tank circuits. Its charge-pump current is digitally programmable across five values (70–900 µA), and the reference divider ratio is selectable via I²C to optimize phase noise vs. lock time trade-offs.

It features dual-path IF amplification: a differential digital IF output (DIF OUT1/OUT2) optimized for 44 MHz IF with 117 dBµV output level, and a single-ended analog IF output (AIF OUT) at 45.75 MHz. The IF GCA provides 0–3 V control voltage input, enabling 66 dB linear-in-dB gain adjustment, while the RF AGC circuit offers programmable start-point (102–114 dBµV) and current mode (300 nA/9 µA).

Key Specifications

Pinout & Package

SN761640DBTR is housed in a 44-pin Thin Shrink Small-Outline Package (TSSOP), DBT suffix, with exposed thermal pad (not electrically connected). Pin numbering follows standard top-view layout with pin 1 at bottom-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital TV tuner applications.

Compared with SI2151-A10-GM and MAX2161ETJ+, the SN761640DBTR uniquely retains full external VCO control, 5-V operation, high-voltage VTU, and discrete band-switch drivers - making it suitable for high-performance fixed-installation digital TV tuners requiring design flexibility and legacy compatibility.

Availability

SN761640DBTR is available at Aetrix Electronics and suitable for digital TV receivers, cable set-top boxes, and broadcast monitoring equipment requiring stable component supply, long-term lifecycle support, and traceable sourcing from authorized channels.

Supply support for SN761640DBTR 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 connectivity technologies, with decades of expertise in broadcast and communications ICs.

The SN761640DBTR belongs to TI's legacy digital TV tuner product line, engineered specifically for high-fidelity terrestrial and cable TV signal reception with emphasis on phase noise, gain stability, and flexible band-switching architecture.

FAQ

What is the primary function of the SN761640DBTR in a digital TV system?

The SN761640DBTR serves as a complete front-end tuner IC that performs RF-to-IF downconversion for VHF-L, VHF-H, and UHF bands. It integrates a PLL synthesizer, three independent oscillator sections, mixer, RF AGC detector, and IF gain-controlled amplifier - enabling a single-chip solution for DVB-T, ATSC, and ISDB-T signal acquisition before demodulation.

Does the SN761640DBTR support both analog and digital IF outputs?

Yes, the SN761640DBTR supports both output types. It provides a single-ended analog IF output (AIF OUT, pin 13) at 45.75 MHz and differential digital IF outputs (DIF OUT1/DIF OUT2, pins 14/15) at 44 MHz. Selection between them is controlled via I²C register bit T2/IFDA in Control Byte 2 (CB2).

How is band selection implemented on the SN761640DBTR?

Band selection is executed using four NPN-type band-switch drivers (BS1–BS4, pins 31–33, 44). These open-collector outputs sink up to 10 mA each and drive external transistor switches. Specific combinations (e.g., BS1=1/BS2=0 for VHF-L) route RF input to the appropriate oscillator/mixer path, as defined in the functional description table.

What is the role of the VTU pin on the SN761640DBTR?

The VTU pin (pin 11) is the high-voltage tuning amplifier output, delivering 30–33 V to varactor diodes in external VCO tank circuits. It features low off-state leakage (<10 µA) and supports wide tuning ranges essential for covering full VHF/UHF broadcast bands with high Q-factor resonators.

Can the SN761640DBTR operate with a 3.3-V supply?

No, the SN761640DBTR requires a 4.5–5.5-V supply (VCC, pin 17) and is not 3.3-V compatible. Its internal PLL, mixer, oscillator biasing, and band-switch drivers are designed exclusively for 5-V operation, as confirmed by absolute maximum ratings and recommended operating conditions in the datasheet.