FAN3850AUC19X - FAIRCHILD SEMICONDUCTOR

July 2011

FAN3850A • Rev. 3.0.6

FAN3850A — Microphone Pre-Amplifier with Digital Output

FAN3850A

Microphone Pre-Amplifier with Digital Output

Features

 Optimized for Mobile Handset and Notebook PC

Microphone Applications

 Accepts Input from Electret Condenser

Microphones (ECM)

 Pulse Density Modulation (PDM) Output

 Standard 5-Wire Digital Interface

 16dB and 19dB Gain Versions Available(1)

 Low Input Capacitance, High PSR, 20kHz

Pre-Amplifier

 Low-Power 1.5μA Sleep Mode

 Typical 470μA Supply Current

 SNR of 62/61dB(A) for 16/19dB Gain Respectively

 Total Harmonic Distortion 0.02%

 Input Clock Frequency Range of 1-4MHz

 Integrated Low Drop-Out Regulator (LDO)

 Small 1.26mm x 0.86mm 6-Ball WLCSP Package

Description

The FAN3850A integrates a pre-amplifier, LDO, and

ADC that converts Electret Condenser Microphone

(ECM) outputs to digital Pulse Density Modulation

(PDM) data streams. The pre-amplifier accepts analog

signals from the ECM and drives an over-sampled

sigma delta Analog-to-Digital Converter (ADC) and

outputs PDM data. The PDM digital audio has the

advantage of noise rejection and easy interface to

mobile handset processors.

The FAN3850A features an integrated LDO and is

powered from the system supply rails up to 3.63V, with

low power consumption of only 0.85mW and less than

20W in Power-Down Mode.

Applications

 Electret Condenser Microphones with Digital Output

 Mobile Handset

 Headset Accessories

 Personal Computer (PC)

.

Ordering Information

Part Number

Operating

Temperature

Range

Package Packing

Method

FAN3850AUC16X -30°C to +85°C 6 Ball, Wafer-Level Chip-Scale Package (WLCSP) 3000 Units on

Tape & Reel

FAN3850AUC19X -30°C to +85°C 6-Ball, Wafer-Level Chip-Scale Package (WLCSP) 3000 Units on

Tape & Reel

Note:

1. Alternate gain options are possible. Please contact Fairchild.

FAN3850A • Rev. 3.0.6 2

FAN3850A — Microphone Pre-Amplifier with Digital Output

Block Diagram

Figure 1. Block Diagram

Pin Configuration

Figure 2. Pin Assignments

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

LDO

Pre-Amp 6'

ADC

INPUT

Sleep

Mode Ctrl

DATA

SELECT

CLOCK

VDD

GND

FAN3850A • Rev. 3.0.6 3

FAN3850A — Microphone Pre-Amplifier with Digital Output

Absolute Maximum Ratings

Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be

operable above the recommended operating conditions and stressing the parts to these levels is not recommended.

In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability.

The absolute maximum ratings are stress ratings only.

Symbol Parameter Min. Max. Unit

VDD DC Supply Voltage -0.3 4.0 V

VIO Analog and Digital I/O -0.3 VCC+0.3 V

ESD

Human Body Model, JESD22-A114, All Pins Except

Microphone Input ±7 kV

Human Body Model, JESD22-A114 – Microphone Input ±300 V

Note:

2. This device is fabricated using CMOS technology and is therefore susceptible to damage from electrostatic

discharges. Appropriate precautions must be taken during handling and storage of this device to prevent

exposure to ESD.

Reliability Information

Symbol Parameter Min. Typ. Max. Unit

TJ Junction Temperature +150 °C

TSTG Storage Temperature Range -65 +125 °C

TRFLW Peak Reflow Temperature +260 °C

4JA Thermal Resistance, JEDEC Standard,

Multilayer Test Boards, Still Air 90 °C/W

Recommended Operating Conditions

The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended

operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not

recommend exceeding them or designing to Absolute Maximum Ratings.

Symbol Parameter Min. Typ. Max. Unit

TA Operating Temperature Range -30 +85 °C

VDD Supply Voltage Range 1.64 1.80 3.63 V

tRF-CLK Clock Rise and Fall Time 10 ns

FAN3850A • Rev. 3.0.6 4

FAN3850A — Microphone Pre-Amplifier with Digital Output

Device Specific Electrical Characteristics

Unless otherwise specified, all limits are guaranteed for TA=25°C, VDD=1.8V, VIN=94dB (SPL), and fCLK=2.4MHz.

Duty Cycle=50% and CMIC=15pF.

Symbol Parameter FAN3850AUC16X FAN3850AUC19X Unit

Min. Typ. Max. Min. Typ. Max.

SNR Signal-to-Noise Ratio

fIN=1kHz (1Pa), A-Weighted 62 61 dB(A)

eN Total Input RMS Noise(4)

20Hz to 20kHz, A-Weighted 5.74 6.80 4.45 5.30 μVRMS

VIN Maximum Input Signal

fIN=1kHz, THD+N < 10%, Level=0V 448 317 mVPP

Electrical Characteristics

Unless otherwise specified, all limits are guaranteed for TA=25°C, VDD=1.8V, VIN=94dB (SPL), and fCLK=2.4MHz.

Duty Cycle=50% and CMIC=15pF.

Symbol Parameter Condition Min. Typ. Max. Unit

VDD Supply Voltage Range 1.64 1.80 3.63 V

IDD Supply Current INPUT=AC Coupled to GND,

CLOCK=On, No Load 470 A

ISLEEP Sleep Mode Current fCLK=GND 1.5 8.0 A

PSR Power Supply Rejection(4)

INPUT=AC Coupled to GND,

Test Signal on VDD=217Hz

Square Wave and

Broadband Noise(3), Both

100mVP-P

-74 dBFS

INNOM Nominal Sensitivity(5) INPUT=94dBSPL (1Pa)

-26 dBFS

THD Total Harmonic Distortion(6) f

IN=1kHz, INPUT=-26dBFS 0.02 0.20 %

THD+N THD and Noise(4)

50Hz  fIN  1kHz,

INPUT=-20dBFS 0.2 1.0

%

fIN=1kHz, INPUT=-5dBFS 1.0 5.0

fIN=1kHz, INPUT=0dBFS 5.0 10.0

CIN Input Capacitance(7) INPUT

0.2 pF

RIN Input Resistance(7) INPUT >100 G

VIL CLOCK & SELECT Input

Logic LOW Level

0.3 V

VIH CLOCK & SELECT Input

Logic HIGH Level 1.5 V

DD+0.3 V

VOL Data Output Logic LOW

Level

0.35*VDD V

VOH Data Output Logic HIGH

Level 0.65*VDD

V

VOUT Acoustic Overload Point(7) THD < 10% 120

dBSPL

Continued on the following page…

FAN3850A • Rev. 3.0.6 5

FAN3850A — Microphone Pre-Amplifier with Digital Output

Electrical Characteristics (Continued)

Unless otherwise specified, all limits are guaranteed for TA=25°C, VDD=1.8V, VIN=94dB(SPL), and fCLK=2.4MHz.

Duty Cycle=50% and CMIC=15pF.

Symbol Parameter Condition Min. Typ. Max. Unit

tA Time from CLOCK Transition

to Data becoming Valid

On Falling Edge of CLOCK,

SELECT=GND, CLOAD=15pF 18 43 ns

tB Time from CLOCK Transition

to Data becoming HIGH-Z

On Rising Edge of CLOCK,

SELECT=GND, CLOAD=15pF 0 5 16

ns

tA Time from CLOCK Transition

to Data becoming Valid

On Rising Edge of CLOCK,

SELECT=VDD, CLOAD=15pF 18 56 ns

tB Time from CLOCK Transition

to Data becoming HIGH-Z

On Falling Edge of CLOCK,

SELECT=VDD, CLOAD=15pF 0 5 16

ns

fCLK Input CLOCK Frequency(8) Active Mode 1.0 2.4 4.0 MHz

CLKdc CLOCK Duty Cycle(4) 40 50 60 %

tWAKEUP Wake-Up Time(9) f

CLK=2.4MHz 0.35 2.00 ms

tFALLASLEEP Fall-Asleep Time(10) f

CLK=2.4MHz 0 0.01 1.00 ms

CLOAD Load Capacitance on Data 100 pF

Notes:

3. Pseudo-random noise with triangular probability density function. Bandwidth up to 10MHz.

4. Guaranteed by characterization.

5. Assuming that 120dB(SPL) is mapped to 0dBFS.

6. Assuming an input of -45dBV

7. Guaranteed by design.

8. All parameters are tested at 2.4MHz. Frequency range guaranteed by characterization.

9. Device wakes up when fCLK  300kHz.

10. Device falls asleep when fCLK  70kHz.

Figure 3. Interface Timing

FAN3850A • Rev. 3.0.6 6

FAN3850A — Microphone Pre-Amplifier with Digital Output

Typical Performance Characteristics

Unless otherwise specified, all limits are guaranteed for TA=25°C, VDD=1.8V, VIN=94dB(SPL), fCLK=2.4MHz, and duty

cycle=50%.

Figure 4. Noise vs. Frequency

Figure 5. THD, SINDA, and SNR vs. Input Amplitude

10

1

10

2

10

3

10

4

10

5

10

6

-160

-140

-120

-100

-80

-60

-40

-20

Frequency [Hz]

Amplitude [dBFS]

Amplitude Spectrum [dBFS], Fo = 1000.2135 Hz, Fs = 2.400000 MHz, SNR = 56.89 dB, SNR = 60.88 dB(A), THD = 0.008 %

m

Fo(0)= -26.15 dBFS

m

Fo(1)= -110.28 dBFS

m

Fo(2)= -116.40 dB FS

m

Fo(3)= -120.45 dBFS

m

Fo(4)= -125.03 dBFS

p

Integrat ed Noise = -87.03 dBFS(A)

p

Spur = -101.34 dBFS, SFDR = 75.19 dBc

Noise

Noise(A)

Signal

Filename: fan3850a-1-BD9

2

M-20110125T122914.dat

THD = 81.95 dB

SNR = 60.88 dBc(A)

SINAD = 56.87 dB

ENOB = 13.50

N = 2097152 pts

Blackman Window

FAN3850A • Rev. 3.0.6 7

FAN3850A — Microphone Pre-Amplifier with Digital Output

Typical Performance Characteristics (Continued)

Figure 6. THD, SINAD, and SNR vs. Output Level

Figure 7.  Gain vs. Temperature (Nominal Temperature= 25°C)

Temp(C) Delta(dB)

40 0.1971

30 0.1644

20 0.1260

10 0.0954

0 0.0657

10 0.0359

20 0.0139

25 0.0000

30 0.0097

40 0.0344

50 0.0514

60 0.0739

70 0.0998

80 0.1183

85 0.1271

403020100 1020304050607080

4

3

2

1

0

1

2

3

4

JunctionTemperatureTjC

Gain(dB)

FAN3850A • Rev. 3.0.6 8

FAN3850A — Microphone Pre-Amplifier with Digital Output

Applications Information

Figure 8. Mono Microphone Application Circuit

Figure 9. Stereo Microphone Application Circuit

L/R

Decimation

VDD

Interpolation

SELECT

SPEAKER

Applications Software

ADC

SELECT

CLK

Pre-

Amp

SDI

ADC

INPUT

SDO

Pre-

Amp

DATA

INPUT

CLOCK

VDD

Serial Port

CLOCK

Audio

Output

DATA

Low Pass Filter Noise Shaper

Decimation

Noise Shaper

Low Pass Filter

INPUT

Serial Port

CLK

Pre-

Amp

Applications Software

ADC

Interpolation

CLOCK

SDI

DATA

SPEAKER

VDD

SELECT

SDO

Audio

Output

L/R

FAN3850A • Rev. 3.0.6 9

FAN3850A — Microphone Pre-Amplifier with Digital Output

Applications Information (Continued)





Diaphragm

Backplate

A

irgap

Electre

t

FAN3850A

INPUT

CLOCK

DATA

SELECT

V

DD

GND

Figure 10. MIC Element Drawing

A 0.1μF decoupling capacitor is required for VDD. It can

be located inside the microphone or on the PCB very

close to the VDD pin.

Due to high input impedance, care should be taken to

remove all flux used during the reflow soldering process.

A 100 resistance is recommended on the clock output

of the device driving the FAN3850A to minimize ringing

and improve signal integrity.

For optimal PSR, route a trace to the VDD pin. Do not

place a VDD plane under the device.

FAN3850A • Rev. 3.0.6 10

FAN3850A — Microphone Pre-Amplifier with Digital Output

Physical Dimensions

Figure 11. 6-Ball, Wafer-Level Chip-Scale Package (WLCSP)

FAN3850A External Product Dimensions

Product ID D E X Y

All options 1.260mm 0.860mm 0.145mm 0.145mm

Ball Composition: SN97.5-Ag2.5

Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner

without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify

or obtain the most recent version. Package specifications do not expand Fairchild’s worldwide terms and conditions, specifically the

warranty therein, which covers Fairchild products.

Always visit Fairchild Semiconductors online packaging area for the most recent packaging drawings and tape and reel

specifications. http://www.fairchildsemi.com/packaging/.

BOTTOM VIEW

TOP VIEW

12

A

B

C

6X

0.005 C

A

B

(X) +/-0.018

(Y) +/-0.018

Ø0.120±0.010

F

E

D

B

A

PIN A1

A

REA

F

2X

(Ø0.120)

CU PAD

SIDE VIEWS

0.06 C

D

CSEATING

PLANE

0.03 C

NOTES:

A

. NO JEDEC REGISTRATION APPLIES.

B. DIMENSIONS ARE IN MILLIMETERS.

C. DIMENSIONS AND TOLERANCES PER

ASME Y14.5M, 1994.

D. DATUM C, THE SEATING PLANE IS DEFINED

BY THE SPHERICAL CROWNS OF THE BALLS.

E. PACKAGE TYPICAL HEIGHT IS 273 MICRONS

±23 MICRONS (254-300 MICRONS).

F. FOR DIMENSIONS D, E, X, AND Y SEE

PRODUCT DATASHEET.

G. DRAWING FILENAME: UC006AHrev3.

E0.080±0.010

0.570

0.485

0.197±0.013

0.300

0.254

0.570

0.485

RECOMMENDED LAND

PATTERN (NSMD)

(Ø0.220)

SOLDER MASK

A

1

0.01 C

FAN3850A • Rev. 3.0.6 11

FAN3850A — Microphone Pre-Amplifier with Digital Output