FAN3850T Microphone Pre-Amplifier with Temperature Compensation and Digital Output March 2012 FAN3850T Microphone Pre-Amplifier with Temperature Compensation and Digital Output Description Features The FAN3850T integrates a pre-amplifier, LDO, and Optimized for Mobile Handset and Notebook PC Analog-to-Digital Converter (ADC) to convert Electret Microphone Applications Condenser Microphone (ECM) outputs to digital Pulse Density Modulation (PDM) data streams. The pre- Accepts Input from Electret Condenser Microphones amplifier accepts analog signals from the ECM and drives Pulse Density Modulation (PDM) Output an over-sampled sigma delta ADC and outputs PDM data. The PDM digital audio has the advantage of noise Standard 5-Wire Digital Interface rejection and interface-to-mobile handset processors. Amplifier Gain: 15.7dB or 13.7dB The FAN3850T is powered from the system supply rails Negative Temperature Coefficient to Compensate for up to 3.63V, with a low power consumption of only ECM Positive Temperature Coefficient 0.85mW, and less than 20W in Power-Down Mode. The device compensates for the temperature variation Low Input Capacitance, High PSR, 20kHz of the microphone element to achieve a flat sensitivity Pre-Amplifier response over-temperature. Low-Power, 1.5A Sleep Mode Typical 420A Supply Current Signal to Noise Ratio of 62.4dB(A) Sleep LDO Total Harmonic Distortion: 0.01% Mode Ctrl Input Clock Frequency Range of 1-4MHz INPUT CLOCK Integrated Low Drop-Out Regulator (LDO) Pre-Amp Small 1.26mm x 0.86mm 6-Ball WLCSP ADC DATA SELECT Applications GND Electret Condenser Microphones with Digital Output Figure 1. Block Diagram Mobile Handsets Headset Accessories Personal Computers (PC) Ordering Information Gain Operating Packing Part Number Package Option Temperature Range Method FAN3850TUC15X35 15.7dB 6-Ball, Wafer-Level Chip-Scale 3000 Unit -30C to +85C Package (WLCSP) Tape & Reel FAN3850TUC13X35 13.7dB Note: 1. Alternate gain options and temperature coefficient slopes are possible. Please contact a Fairchild representative. 2011 Fairchild Semiconductor Corporation www.fairchildsemi.com FAN3850T Rev. 3.0.2 FAN3850T Microphone Pre-Amplifier with Temperature Compensation and Digital Output Pin Configuration Figure 2. Pin Configuration (Top View) Pin Definitions Pin Name Type Description A1 CLOCK Input Clock Input B1 GND Input Ground Pin C1 DATA Output PDM Output 1-Bit ADC A2 SELECT Input Rising or Falling Clock-Edge Select B2 INPUT Input Microphone Input C2 VDD Input Device Power Pin 2011 Fairchild Semiconductor Corporation www.fairchildsemi.com FAN3850T Rev. 3.0.2 2