[AK4637]
AK4637
24bit Mono CODEC with MIC/SPK-AMP
1. General Description
The AK4637 is a low power 24-bit Mono CODEC with a microphone and speaker amplifiers.
The AK4637 supports sampling frequency from 8kHz to 48kHz. It is suitable for a wide range of
application from speech signal processing for narrowband, wideband and super wideband to sound
signal processing for audio band.
The input circuits include a microphone amplifier and a high performance digital ALC (automatic level
control) circuit. In addition, the output circuits include a speaker amplifier with 1W output power. It is
suitable for various products as well as portable applications with recording/playback function.
The AK4637 are available in a small 20-pin QFN (3mm x 3mm, 0.4mm pitch: AK4637EN) package saving
mounting area on the board.
Application:
IP Camera
Digital Camera
MFP(Multi Function Printer)
2. Features
1.
Recording Functions
Analog Input
1 Monaural Single-ended input or Differential input
Microphone Amplifier: +30dB ~ 0dB, 3dB Step
Microphone Power Supply: 2.0V or 2.4V, Noise Level=
108dBV
Digital ALC (Automatic Level Control)
- Setting Range: +36dB
52.5dB,
0.375dB Step & Mute
ADC Performance: S/(N+D): 83dB, DR, S/N: 88dB (MIC-Amp=+18dB)
S/(N+D): 84dB, DR, S/N: 95dB (MIC-Amp=0dB)
Wind Noise Reduction Filter
5-Band Notch Filter: Include Dynamic Gain Control
Digital Microphone Interface
Playback Functions
Digital ALC (Automatic Level Control)
- Setting Range: +36dB ~
52.5dB,
0.375dB Step & Mute
Sidetone Mixer & Volume Control (0dB ~
18dB,
6dB Step)
Digital Volume Control
- +12dB ~
89.5dB,
0.5dB Step & Mute
Mono Speaker Amplifier (with Line Output Switch)
- Speaker Amplifier Porformance: S/(N+D): 75dB@250mW, S/N: 97 dB
- BTL Output
- Output Power: 400mW@8 (AVDD=3.3V), 1W@8 (AVDD=5V)
Analog Mixing: BEEP Input
Power Management
2.
3.
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4.
Master Clock:
(1) PLL Mode
Frequencies: 11.2896MHz, 12MHz, 12.288MHz, 13.5MHz, 24MHz, 27MHz
(MCKI pin), 16fs, 32fs, 64fs (BICK pin)
(2) External Clock Mode
Frequencies: 256fs, 384fs, 512fs or 1024fs (MCKI pin)
5. Sampling Frequencies
PLL Master Mode:
8kHz, 11.025kHz, 12kHz, 16kHz, 22.05kHz, 24kHz, 32kHz, 44.1kHz, 48kHz
PLL Slave Mode (BICK pin): 8kHz ~ 48kHz
EXT Master/Slave Mode:
8kHz ~ 48kHz (256fs, 384fs, 512fs), 8kHz
24kHz (1024fs)
6. Master/Slave Mode
7. Audio Interface Format: MSB First, 2’s complement
ADC: DSP Mode, 16/24bit MSB justified, 16/24bit I
2
S
DAC: DSP Mode, 16/24bit MSB justified, 16bit LSB justified, 16/24bit I
2
S
8.
P
I/F: I
2
C Bus (Ver 1.0, 400kHz Fast-Mode)
9. Operating Temperature: Ta =
40
85C
10. Power Supply
Analog Power Supply (AVDD): 2.8 ~ 5.5V
Digital Power Supply (DVDD): 1.6 ~ 1.98V
Digital I/O Power Supply (TVDD): 1.6 or (DVDD – 0.2) ~ 3.6V
11. Package:
20-pin QFN (3 x 3 mm, 0.4mm pitch)
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3. Table of Contents
1.
2.
3.
4.
5.
General Description ............................................................................................................................. 1
Features............................................................................................................................................... 1
Table of Contents ................................................................................................................................ 3
Block Diagram ..................................................................................................................................... 5
Pin Configurations and Functions ....................................................................................................... 6
■
Pin Layout .......................................................................................................................................... 6
■
Comparison Table of the AK4951EN................................................................................................. 7
■
PIN/FUNCTION.................................................................................................................................. 9
■
Handling of Unused Pin ..................................................................................................................... 9
6. Absolute Maximum Ratings............................................................................................................... 10
7. Recommended Operating Conditions ............................................................................................... 10
8. Electrical Characteristics ................................................................................................................... 11
■
Analog Characteristics ..................................................................................................................... 11
■
Power Consumption on Each Operation Mode ............................................................................... 13
■
Filter Characteristics ........................................................................................................................ 14
■
DC Characteristics ........................................................................................................................... 15
■
Switching Characteristics ................................................................................................................. 16
■
Timing Diagram ................................................................................................................................ 20
9. Functional Descriptions ..................................................................................................................... 27
■
System Clock ................................................................................................................................... 27
■
Master Mode/Slave Mode ................................................................................................................ 27
■
PLL Mode ......................................................................................................................................... 28
■
PLL Unlock State ............................................................................................................................. 28
■
PLL Master Mode (PMPLL bit = “1”, M/S bit = “1”) .......................................................................... 29
■
PLL Slave Mode (PMPLL bit = “1”, M/S bit = “0”) ............................................................................ 31
■
EXT Slave Mode (PMPLL bit = “0”, M/S bit = “0”) ........................................................................... 32
■
EXT Master Mode (PMPLL bit = “0”, M/S bit = “1”) ......................................................................... 33
■
System Reset ................................................................................................................................... 34
■
Audio Interface Format .................................................................................................................... 35
■
MIC/LINE Input Selector .................................................................................................................. 39
■
Microphone Gain Amplifier............................................................................................................... 39
■
Microphone Power ........................................................................................................................... 40
■
Digital Microphone ........................................................................................................................... 41
■
Digital Block ..................................................................................................................................... 43
■
Digital HPF1 ..................................................................................................................................... 45
■
Digital Programmable Filter Circuit .................................................................................................. 45
■
ALC Operation ................................................................................................................................. 50
■
Input Digital Volume (Manual Mode) ............................................................................................... 56
■
Sidetone Digital Volume ................................................................................................................... 57
■
DAC Input Selector .......................................................................................................................... 57
■
Output Digital Volume ...................................................................................................................... 57
■
Soft Mute .......................................................................................................................................... 58
■
BEEP Input ....................................................................................................................................... 59
■
Speaker Output (SPP/SPN pins, LOSEL bit = “0”) .......................................................................... 60
■
Thermal Shutdown Function ............................................................................................................ 61
■
Monaural Line Output (AOUT pin, LOSEL bit = “1”) ........................................................................ 62
■
Regulator Block ................................................................................................................................ 64
■
Serial Control Interface .................................................................................................................... 65
■
Register Map .................................................................................................................................... 68
■
Register Definitions .......................................................................................................................... 70
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10. Recommended External Circuits....................................................................................................... 82
11. Control Sequence .............................................................................................................................. 84
■
Clock Set Up .................................................................................................................................... 84
■
Microphone Input Recording ............................................................................................................ 87
■
Digital Microphone Input .................................................................................................................. 88
■
Speaker Amplifier Output ................................................................................................................. 89
■
Beep Signal Output from Speaker Amplifier .................................................................................... 90
■
Lineout Output.................................................................................................................................. 91
■
Stop of Clock .................................................................................................................................... 92
■
Power Down ..................................................................................................................................... 93
12. Package ............................................................................................................................................. 94
■
Outline Dimensions .......................................................................................................................... 94
■
Material & Lead finish ...................................................................................................................... 94
■
Marking............................................................................................................................................. 94
13. Ordering Guide .................................................................................................................................. 95
14. Revision History................................................................................................................................. 95
IMPORTANT NOTICE.............................................................................................................................. 96
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4. Block Diagram
VCOM
VSS1
REGFIL
AVDD
DVDD
TVDD
VSS2
PMMP
Analog Block
LDO
2.3V
MIC-Power
Digital Core
SPK-Amp
PDN
Control
Register
SDA
SCL
MPWR
MIC Power
Supply
AVDD
PMADC
Internal
MIC
AIN/IN+/DMDAT
MIC-Amp
+30~0dB
ADC
HPF
PMPFIL
HPF2
BEEP/IN-/DMCLK
BEEP
PMBP
LPF
4-band EQ
ALC
1 Band EQ
BICK
Audio
I/F
FCK
SDTO
PFVOL
SDTI
PMSL
PMDAC
DVOL
SMUTE
SPP/AOUT
Mono
Speaker
SPN
DAC
PMPLL
PLL
MCKI
Figure 1. Block Diagram
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