The LHA9954 is a high-performance, single-chip analog-to-digital converter (ADC). The device includes a low-noise programmable gain amplifier (PGA), delta-sigma modulator, and digital filter. The ADC supports two modes of operation to achieve the best balance between power consumption and resolution.
Two-channel multiplexer can select external signal measurement and internal ADC test signal. There is a mode to test the internal noise by shorting the input circuit. The PGA has high input impedance and low noise, allowing direct connection to sensors such as geophones or hydrophones.
Fourth order intrinsically stable modulator provides excellent low noise and linearity performance. The modulator output is filtered and decimated by an on-chip digital filter to generate an ADC conversion result. Digital filters provide data rates from 250 to 4000 SPS. The high-pass filter (HPF) has a programmable corner frequency. On-chip gain and offset adjustment registers support system calibration. The sync input controls the timing of ADC conversions. A shutdown input puts the ADC in shutdown mode.
The LHA9954 is housed in a compact 24-lead 5mm x 4mm QFN package and is fully rated for –40°C to +85°C operation with a maximum operating temperature range of –50°C to +125°C.

Product Features

  • Optional working mode
  • low power mode

- 7mW

- 127dB SNR250 SPSPGA = 1

  • High resolution mode:

- 12mW

- 135.4dB SNR250 SPSPGA = 1

  • THD:–120dB
  • CMRR127dB
  • Dual Channel Multiplexer
  • Intrinsically stable modulator
  • Fast Response Out-of-Range Detector
  • Flexible digital filters:

- Sinc + Finite Impulse Response (FIR) + Infinite Impulse Response

(IIR) (optional)

- Linear or minimum phase options

- Programmable High Pass Filter

  • Offset Error and Gain Error Calibration
  • SYNC input
  • Analog Power: 5V or ±2.5V
  • Digital Supply: 1.8V to 3.3V

Application Scenario

  • Energy exploration
  • Earthquake monitoring
  • High precision instrument