Texas Instruments 32F8104-CNR

Overview

32F8104-CNR from SSI is a low-power, digitally programmable 7th-order equiripple low-pass filter IC with integrated 7-bit I-DAC and V-DAC for cutoff frequency and boost control. It delivers 2.9–9 MHz programmable ƒc, 0–14.3 dB boost, ±15% ƒc accuracy, ±2% group delay variation, and <1.5% THD in a 16-lead SON package-used in variable-data-rate telecom line drivers and adaptive equalization stages.

For engineers reviewing the 32F8104-CNR datasheet, 32F8104-CNR pinout, 32F8104-CNR application, or 32F8104-CNR equivalent, key selection criteria include its dual-DAC-controlled analog filter response, matched normal/differential outputs, LOWZ input switch behavior, idle-mode power (<5 mW), and absence of external passive components.

Technical Context

The 32F8104-CNR implements a fixed 7th-order 0.05° equiripple low-pass transfer function with real-axis zero pairs enabling symmetrical high-frequency peaking. Its cutoff frequency (ƒc) and boost are independently controlled by two on-chip 7-bit DACs-programmed via a 3-wire serial interface (SCLK, SDI, SDEN)-with no impact on group delay flatness.

It features dual output configurations: VO_NORM+/- (single-ended, low-impedance) and VO_DIFF+/- (differential), both internally matched. The LOWZ pin enables a low-impedance input switch, while PTAT reference and VREF support stable DAC operation across temperature.

Key Specifications

Pinout & Package

16-lead SON (Small Outline No-lead) package, 4 mm × 4 mm, 0.5 mm pitch, exposed thermal pad.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar programmable analog filter applications.

Compared with MAX275ACPP+ and AD8450ARUZ, the 32F8104-CNR uniquely combines digitally tunable 7th-order low-pass filtering, independent boost control, matched dual outputs, and ultra-low idle power-making it the only option for adaptive telecom line drivers requiring both precision analog response and runtime configurability.

Availability

32F8104-CNR is available at Aetrix Electronics and suitable for DSL line drivers, ISDN transceivers, medical imaging data links, and industrial serial backplanes requiring stable component supply and long-term obsolescence management.

Supply support for 32F8104-CNR 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

SSI (Silicon Systems Inc.) was a fabless analog semiconductor company specializing in high-performance mixed-signal ICs for telecommunications infrastructure before acquisition by Texas Instruments in 2002.

The 32F810X family was designed specifically for adaptive analog filtering in variable-data-rate digital subscriber line (xDSL) and ISDN physical layer systems-prioritizing group delay flatness, DAC-controlled tuning, and low-power operation.

FAQ

What is the exact cutoff frequency range supported by the 32F8104-CNR?

The 32F8104-CNR supports a digitally programmable cutoff frequency range of 2.9 MHz to 9 MHz, controlled by its internal 7-bit I-DAC. This range is factory-trimmed and specified with ±15% accuracy across temperature and voltage. The 32F8104-CNR achieves this using a fixed 7th-order equiripple analog topology-no external components are needed to adjust or maintain ƒc.

Does the 32F8104-CNR support differential input and output simultaneously?

Yes, the 32F8104-CNR accepts differential input via VIN+ and VIN−, and provides two independent output configurations: matched single-ended outputs (VO_NORM+/−) and fully differential outputs (VO_DIFF+/−). Both output sets are internally calibrated for gain, phase, and THD matching-enabling flexible interface choices without performance trade-offs in the 32F8104-CNR signal path.

How does the LOWZ pin affect the input stage of the 32F8104-CNR?

The LOWZ pin on the 32F8104-CNR is an active-high digital control that enables a low-impedance input mode, reducing input resistance to support driving long cables or high-capacitance PCB traces. When LOWZ is asserted, the 32F8104-CNR input stage maintains signal integrity under heavy capacitive loading-unlike standard high-Z inputs which would suffer bandwidth degradation.

Can the 32F8104-CNR's boost function be used independently of cutoff frequency tuning?

Yes, the 32F8104-CNR implements two independent 7-bit DACs: one for cutoff frequency (I-DAC) and one for boost (V-DAC). They are programmed separately via the same 3-wire serial interface. Boost remains effective across the full 2.9–9 MHz ƒc range, and adjusting boost has no effect on group delay flatness or cutoff frequency accuracy in the 32F8104-CNR.

What power supply configuration does the 32F8104-CNR require?

The 32F8104-CNR operates from a single +5 V supply applied to VCD (digital) and analog circuitry-no split or negative rails are needed. It consumes 95 mW nominally during active filtering and drops below 5 mW in idle mode when powered but unconfigured. AGND and DGND must be connected at a single point near the 32F8104-CNR to ensure mixed-signal integrity.