Analog Devices Inc. LTC1060CSW

LTC1060CSW Product Summary

The LTC1060CSW from Analog Devices Inc. is a universal switched capacitor filter IC designed to offer versatility and precision for medium-frequency analog signal processing. Housed in a 20-lead SOIC package, this device incorporates two high-performance switched capacitor filter blocks. These can be combined with external resistors to implement a diverse range of second-order filter functions – including lowpass, bandpass, highpass, notch, and allpass – and cascaded for up to fourth-order filtering. The LTC1060CSW is especially noted for achieving a 30kHz cutoff in dual-supply mode, covering applications where precise, tunable, and high-Q analog filtering is crucial.

Main Attributes and Technical Strengths of the LTC1060CSW

The LTC1060CSW leverages Linear Technology's proprietary LTCMOS™ silicon gate process. This advanced process allows the filter IC to achieve superior offset characteristics, excellent center-frequency-to-Q product, and high dynamic range within a robust temperature range. Key features include:

Dual filter architecture, allowing two simultaneous, independent filters per IC.

Precision clock-to-center frequency ratios (50:1, 100:1), ensuring high accuracy of center frequency even across wide temperature swings.

Operable from single (+5V) or dual supplies (±2.37V to ±8V), supporting both lowand high-voltage systems.

High Q-support (selectivity), covering high-performance resonance and narrow-band filtering.

Low crosstalk (70dB typical), vital for multi-channel and mixed-signal environments.

Robust RoHS3 and REACH environmental compliance.

Pinout compatibility with MF10 series, simplifying upgrades in legacy designs.

LTC1060CSW Electrical Specifications and Performance Standards

The LTC1060CSW is designed and trimmed to deliver reliable performance across a range of supply voltages and frequencies. Key specifications include:

Center frequency (fo): 0.1Hz to 30kHz at ±5V (lower at lower supplies).

Maximum clock frequency: Up to 1.5MHz (1.6MHz fo x Q product at high Q).

Clock-to-center frequency accuracy: ±0.8% (mode-dependent).

Supply current: 5–8mA typical at ±5V.

DC offset voltages as low as 2–15mV (depending on conditions).

Gain accuracy: Typically ±0.1% at bandpass output for Q = 10.

Excellent temperature stability with low temperature coefficients for both fo and Q.

Output voltage swing: Up to ±3.8V at ±5V supply.

Op amp bandwidth: 2MHz GBW; slew rate of 7V/μs.

Wide ambient temperature operation: –40°C to +85°C (commercial), –55°C to +125°C (industrial/military grades available).

These metrics ensure stable, predictable filter behavior in demanding signal processing circuits, even under varying environmental and supply conditions.

LTC1060CSW Package Details, Configuration, and Pin Description

The LTC1060CSW is provided in a 20-lead SOIC “Wide” (7.5mm) package, with all critical analog, digital, and clock inputs separated to minimize noise and crosstalk. The device includes clearly defined analog and digital supply pins, level-shifting for clock compatibility down to TTL/CMOS thresholds, and accessible control pins for flexible mode configuration. AGND pin must be carefully managed for optimal filter operation, particularly in single-supply designs where it is typically tied to half-supply potential. The device can be configured for 50:1 or 100:1 clock-to-center frequency operation, depending on the connection at the Hold/50/100-input (Pin 12).

Common Use Cases for the LTC1060CSW

Engineers commonly deploy the LTC1060CSW in systems requiring programmable and high-Q analog filtering where digital signal processing is impractical or uneconomical. Key application domains include:

Bandpass, notch, and allpass analog filters with tunable center frequencies for instrumentation and measurement.

Lowpass and bandpass filters in telecom signal chains, where temperature swing and supply variation demand robust operation.

Tracking filters for data acquisition, supporting variable bandwidth and center frequency via an external clock.

Telecommunication line and channel filters where programmability and low power are critical.

Systems requiring high dynamic range and linearity for precision end equipment operating at medium frequencies up to 30kHz.

A common configuration is a fourth-order bandpass realized by cascading both filter sections in a single 1060CSW, allowing gain and Q adjustment via resistor choice and clock programming.

Design Factors for Choosing and Applying the LTC1060CSW

When specifying the LTC1060CSW, procurement engineers and designers should consider several practical factors to ensure optimal performance:

Supply voltage flexibility: Ensure system rail voltages are compatible with LTC1060CSW’s single or dual supply options.

Clock source quality: Minimize clock jitter and ensure duty cycle is close to 50% for optimal center frequency accuracy and low DC offset.

Mode and external resistor selection: Specific filter configurations (lowpass, bandpass, etc.) depend on appropriate resistor ratios and mode settings; reference the block diagram and application tables for guidance.

Output loading and bandwidth: Account for output signal swing requirements and ensure external loading is within device tolerance.

Ground and bypassing layout: Maintain a clean ground plane and use local 0.1μF bypass capacitors close to supply pins to suppress noise coupling.

Environmental and RoHS compliance: Confirm devices meet project and regulatory standards, particularly for new or export designs.

Alternative or Substitute Models for the LTC1060CSW

For design continuity or cost optimization, engineers may consider the following equivalent or potential replacement devices:

MF10 (by Texas Instruments): Functionally similar switched capacitor filter with compatible pinout and configuration, though specific electrical differences exist.

LTC1060 family (e.g., LTC1060ACN, LTC1060CN): Variants covering different packages or temperature ranges; suitable for alternate sourcing within the same circuit family.

Custom assembled active filter modules: In lower frequency or less demanding applications, discrete op amp and capacitor/resistor combinations may offer an alternative, albeit with less integration and higher component count.

Engineers must verify compatibility regarding supply range, package footprint, and guaranteed performance metrics when selecting alternatives.

Conclusion

The Analog Devices LTC1060CSW is a versatile, high-accuracy universal switched capacitor filter IC engineered to address a broad range of medium-frequency analog filtering requirements. Its robust performance, flexible power supply options, and high configurability make it a go-to solution for precision analog filtering in communications, instrumentation, and industrial signal processing. By closely considering the device’s operational characteristics and integration requirements – and being aware of viable alternatives – engineers and procurement specialists can achieve optimal performance and supply chain reliability in their signal chain designs.