ASAHI KASEI [AK4309B] AK4309B 16Bit SCF DAC for Multimedia General Description The AK4309B is a 1bit stereo DAC for multimedia audio systems. A 1bit DAC can achieve monotonicity and low distortion with no adjustment and is superior to traditional R-2R ladder based DACs. In the AK4309B, the loss of accuracy from clock jitter is also improved by using SCF techniques for on-chip post filter. The AK4309B includes continuous time filter with single end output and does not need any external parts. The master clock can be either 256fs or 384fs, supporting various audio environment. Features Sampling Rate Ranging from 8kHz to 50kHz On chip Perfect filtering • 8 times FIR Interpolator • 2nd order SCF and CTF • Total Response: ±0.5dB at 20kHz On chip Buffer with Single End Output Master Clock: 256fs or 384fs High Tolerance to Clock Jitter TTL Level Digital Interface THD+N: -84dB Dynamic Range: 90dB Output Level: 3.4Vpp Power Supply: 5V±10% Low Power Dissipation: 80mW at 5V Small Package: 20pin SSOP Pin Compatible with AK4310/4309A 0177-E-00 1997/6 -1- ASAHI KASEI [AK4309B] Ordering Guide AK4309BVM AKD4309B 20pin SSOP(0.65mm pitch) -10∼ +70°C Evaluation Board (AK4309B's board is the same as AK4310's) Pin Layout Compatibility with AK4310/09A Parameter Power Supply Digital I/F level DR Output Voltage Click Noise Function of Pin 4 Package AK4310 3∼ 5.5V AK4309A 4.5∼ 5.5V AK4309B 4.5∼ 5.5V CMOS 92dB 2.8Vpp High TTL 91dB 3.4Vpp Middle TTL 90dB 3.4Vpp Low NC 20SSOP PD PD 24SSOP 24SSOP 0177-E-00 1997/6 -2- ASAHI KASEI [AK4309B] PIN/FUNCTION No. Pin Name I/O 1 TST1 I 2 3 4 5 DVDD DVSS NC RST I 6 MCLK I 7 CKS I 8 BICK I 9 SDATA I 10 LRCK I 11 12 13 AOUTR AOUTL VCOM O O O 14 15 16 17 18 AVDD AVSS NC NC VREFH - 19 20 VREFL DZF I O I Function Test Pin (Pull-down pin) Must be left floating or tied to DVSS. Digital Power Supply Pin Digital Ground Pin No Connection Reset Pin When at "L", the AK4309B is in power-down mode and is held in reset. The AK4309B should always be reset upon power-up. Master Clock Input Pin An external TTL clock should be input on this pin. The fs is selected by CKS pin. Master Clock Select Pin "L": MCLK=256fs, "H": MCLK=384fs Serial Bit Input Clock Pin This clock is used to latch SDATA. Serial Data Input Pin 2's complement MSB-first data is input on this pin. L/R Clock Pin This input determines which channel is currently being input on the Serial Data Input pin, SDATA. "H": Lch, "L": Rch Rch analog output pin Lch analog output pin Common Voltage pin, AVDD/2 Normally connected to AVSS with a 0.1uF ceramic capacitor in parallel with a 10uF electrolytic cap. Analog Power Supply Pin Analog Ground Pin No Connection "H" Voltage Reference Input Pin The differential Voltage between VREFH and VREFL inputs set the analog output range. The VREFH pin is normally connected to AVDD and the VREFL pin is connected to AVSS. A 0.1uF ceramic capacitor should be as near to both pins. "L" Voltage Reference Input Pin Zero Input Detect Pin When SDATA of both channels follow a total 8192 LRCK cycles with "0" input data, this pin goes "H". * NC pins are not bonded internally. 0177-E-00 1997/6 -3- ASAHI KASEI [AK4309B] ABSOLUTE MAXIMUM RATINGS (AVSS,DVSS=0V; Note 1 ) Parameter Power Supplies: Analog Digital DVDD-AVDD Input Current, Any Pin Except Supplies Input Voltage Ambient Operating Temperature Storage Temperature Symbol AVDD DVDD VDA IIN VIND Ta Tstg min -0.3 -0.3 -0.3 -10 -65 max 6.0 6.0 0.3 ±10 AVDD+0.3 70 150 Units V V V mA V °C °C Note: 1 . All voltages with respect to ground. WARNING: Operation at or beyond these limits may result in permanent damage to the device. Normal operation is not guaranteed at these extremes. RECOMMENDED OPERATING CONDITIONS (AVSS,DVSS=0V; Note 1 ) Parameter Power Supplies: Analog Digital Voltage Reference(VREFH) (Note 2 ) (Note 3 ) Symbol min typ max Units AVDD DVDD VREF 4.5 4.5 3.0 5.0 5.0 - 5.5 AVDD AVDD V V V Notes: 2 . AVDD and DVDD should be powered at the same time or AVDD should be powered earlier than DVDD. 3 . Analog output voltage scales with the voltage of VREFH at VREFL=AVSS. AOUT(typ.@0dB)=3.4Vpp*VREFH/5. * AKM assumes no responsibility for the usage beyond the conditions in this data sheet. 0177-E-00 1997/6 -4- ASAHI KASEI [AK4309B] ANALOG CHARACTERISTICS (Ta=25°C ; AVDD,DVDD=5.0V; VREFH=AVDD,VREFL=AVSS; fs=44.1kHz; Signal Frequency=1kHz; Measurement Bandwidth=10Hz∼ 20kHz; RL≥ 10kΩ ; unless otherwise specified) Parameter min Resolution typ max Units 16 Bits Dynamic Characteristics (Note 4 ) THD+N (0dB Output) Dynamic Range (-60dB Output, A weight) S/N (A weight) Interchannel Isolation(1kHz) 85 85 80 -84 90 90 90 -79 dB dB dB dB 0.15 60 0.3 - dB ppm/°C 3.4 3.57 Vpp kΩ 13 3 18 5 mA mA 10 50 uA 80 50 50 115 250 mW uW dB DC Accuracy Interchannel Gain Mismatch Gain Drift (Note 5 ) DC Accuracy Output Voltage Load Resistance (Note 6 ) 3.23 10 Power Supplies Power Supply Current Normal Operation ( RST = "H") AVDD DVDD Power-Down-Mode ( RST = "L") AVDD+DVDD (Note 7 ) Power Dissipation (AVDD+DVDD) Normal Operation Power-Down-Mode (Note 7 ) Power Supply Rejection (Note 8 ) Notes: 4 . Measured by AD725C(SHIBASOKU). Averaging mode. Refer to the eva board manual. 5 . The voltage on VREFH pin is held +5V externally. 6 . Full-scale voltage(0dB). Output voltage scales with the voltage of VREH-VREFL. AOUT(typ.@0dB)=3.4Vpp*(VREFH-VREFL)/5. 7 . Power Dissipation in the power-down mode is applied with no external clocks (MCLK,BICK,LRCK held "H" or "L"). 8 . PSR is applied to AVDD,DVDD with 1kHz, 100mVpp. VREF pin is held +5V. 0177-E-00 1997/6 -5- ASAHI KASEI [AK4309B] FILTER CHARACTERISTICS (Ta=25°C ; AVDD,DVDD=4.5V∼ 5.5V; fs=44.1kHz) Parameter Symbol min typ max Units PB 0 24.3 22.05 20.0 - Digital Filter Passband -0.2dB (Note 9 ) -6.0dB (Note 9 ) Stopband Passband Ripple Stopband Attenuation Group Delay (Note 10 ) SB PR SA GD 41 - 14.5 - kHz kHz kHz dB dB 1/fs - ±0.5 - dB ±0.05 Digital Filter + SCF + CTF Frequency Response 0∼ 20.0kHz Note: 9 . The passband and stopband frequencies scale with fs. For example, PB=0.4535*fs(@-0.2dB), SB=0.55*fs. 10 . The calculating delay time which occurred by digital filtering. This time is from setting the 16bit data of both channels to input register to the output of analog signal. DIGITAL CHARACTERISTICS (Ta=25°C ; AVDD,DVDD=4.5∼ 5.5V) Parameter Symbol min typ max Units VIH VIL VOH VOL Iin 2.2 DVDD-0.5 - - 0.8 0.5 ±10 V V V V uA High-Level Input Voltage Low-Level Input Voltage High-Level Output Voltage (Iout=-100A) Low-Level Output Voltage (Iout=100A) Input Leakage Current 0177-E-00 - 1997/6 -6- ASAHI KASEI [AK4309B] SWITCHING CHARACTERISTICS (Ta=25°C ; AVDD,DVDD=4.5∼ 5.5V; CL=20pF) Parameter Master Clock Timing Symbol 256fs: Pulse Width Low Pulse Width High 384fs: Pulse Width Low Pulse Width High LRCK Frequency Duty Cycle Serial Interface Timing BICK Period BICK Pulse Width Low Pulse Width High BICK rising to LRCK edge LRCK Edge to BICK rising SDATA Hold Time SDATA Setup Time fCLK tCLKL tCLKH fCLK tCLKL tCLKH fs Duty (Note 11 ) (Note 11 ) tBCK tBCKL tBCKH tBLR tLRB tSDH tSDS min typ 2.048 28 28 3.072 23 23 8 45 max Unit 12.8 MHz ns ns MHz ns ns kHz kHz % 19.2 44.1 312.5 100 100 50 50 50 50 50 55 ns ns ns ns ns ns ns Reset Timing RST Pulse Width (Note 12 ) tRST 150 Notes: 11 . BICK rising edge must not occur at the same time as LRCK edge. 12 . The AK4309B can be reset by bringing RST "L" to "H" only upon power up. 0177-E-00 ns 1997/6 -7- ASAHI KASEI [AK4309B] Timing Diagram 0177-E-00 1997/6 -8- ASAHI KASEI [AK4309B] OPERATION OVERVIEW System Clock The external clocks which are required to operate the AK4309B are MCLK, LRCK, BICK. The master clock(MCLK) should be synchronized with LRCK but the phase is not critical. The MCLK is used to operate the digital interpolation filter and the delta-sigma modulator. The frequency of MCLK is determined by the sampling rate (LRCK), CKS pin. Table 1 illustrates corresponding clock frequencies. When the 384fs is selected, the internal master clock becomes 256fs(=384fs*2/3). Refer to Figure 1 . All external clocks(MCLK,BICK,LRCK) should always be present whenever the AK4309B is in normal operation mode(RST="H"). If these clocks are not provided, the AK4309B may draw excess current because the device utilizes dynamic refreshed logic internally. If the external clocks are not present, the AK4309B should be in the power-down mode(RST ="L"). After exiting reset at power-up etc., the AK4309B is in powerdown mode until MCLK and LRCK are input. Clock frequency 8k∼ 50kHz ∼ 64fs LRCK (fs) BICK MCLK CKS="L" CKS="H" 256fs 384fs Table 1 . System Clocks Figure 1 . MCLK divider Audio Serial Interface Format Data is shifted in via the SDATA pin using BICK and LRCK inputs. A serial data is MSB-first, 2's compliment format and is latched by the rising edge of BICK. Figure 2 . Data Input Timing 0177-E-00 1997/6 -9- ASAHI KASEI [AK4309B] Zero detection When the input data at both channels are continuously zeros for 8192 LRCK cycles, DZF goes to "H". DZF immediately goes "L" if input data are not zero after going DZF "H". System Reset The AK4309B should be reset once by bringing RST "L" upon power-up. The AK4309B is powered up and the internal timing starts clocking by LRCK "↑ " after exiting reset and power down state by MCLK. The AK4309B is in power-down mode until LRCK is input. SYSTEM DESIGN Figure 3 shows the system connection diagram. An evaluation board[AKD4310] is available which demonstrates the optimum layout, power supply arrangements and measurement results. Figure 3 . Typical Connection Diagram Notes: - LRCK=fs, BICK≥ 32fs, MCLK=256fs at CKS="L", MCLK=384fs at CKS="H". - Power lines of AVDD and DVDD should be distributed separately from the point with low impedance of regulator etc. - When AOUT drives some capacitive load, some resistor should be added in series between AOUT and capacitive load. - The capacitor value on VCOM depends on low frequency noise level of power supply. 0177-E-00 1997/6 - 10 - ASAHI KASEI [AK4309B] 1. Grounding and Power Supply Decoupling To minimize coupling by digital noise, decoupling capacitors should be connected to AVDD and DVDD, respectively. AVDD is supplied from analog supply in system and DVDD is supplied from AVDD via 10Ω resistor as shown in Figure 3 . Alternatively if AVDD and DVDD are supplied separately, AVDD and DVDD should be powered at the same time or AVDD should be powered earlier than DVDD. Analog ground and digital ground should be connected together near to where the supplies are brought onto the printed circuit board. Decoupling capacitors for high frequency should be placed as near as possible. 2. Voltage reference The differential Voltage between VREFH and VREFL set the analog output range. VREFH pin is normally connected to AVDD and VREFL pin is connected to AVSS with a 0.1uF ceramic capacitor. VCOM is a signal ground of this chip. An electrolytic capacitor of around 10uF in parallel with a 0.1uF ceramic capacitor attached to these pins eliminates the effects of high frequency noise. No load current may be drawn from VCOM pin. All signals, especially clocks, should be kept away from the VREF and VCOM pins in order to avoid unwanted coupling into the AK4309B. 3. Analog Outputs The analog outputs are also single-ended and centered around the VCOM voltage. The output signal range is typically 3.4Vpp. AC coupling capacitors of larger than 1uF are recommended. The internal switched-capacitor filter and continuous-time filter attenuate the noise generated by the delta-sigma modulator beyond the audio passband. Therefore, any external filters are not required for typical application. The output voltage is a positive full scale for 7FFFH(@16bit) and a negative full scale for 8000H(@16bit). The ideal output is VCOM voltage for 0000H(@16bit). DC offsets on analog outputs are eliminated by AC coupling since analog outputs have DC offsets of VCOM + a few mV. 0177-E-00 1997/6 - 11 - ASAHI KASEI [AK4309B] PACKAGE z 20pin SSOP (Unit: mm) NOTE: Dimension “*” does not include mold flash. Package & Lead frame material Package molding compound : Lead frame material : Lead frame surface treatment : Epoxy Cu Solder plate 0177-E-00 1997/6 - 12 - ASAHI KASEI [AK4309B] MARKING Contents of AAXXXX AA: Lot# XXXX: Date Code 0177-E-00 1997/6 - 13 - IMPORTANT NOTICE zThese products and their specifications are subject to change without notice. Before considering any use or application, consult the Asahi Kasei Microsystems Co., Ltd. (AKM) sales office or authorized distributor concerning their current status. zAKM assumes no liability for infringement of any patent, intellectual property, or other right in the application or use of any information contained herein. zAny export of these products, or devices or systems containing them, may require an export license or other official approval under the law and regulations of the country of export pertaining to customs and tariffs, currency exchange, or strategic materials. zAKM products are neither intended nor authorized for use as critical components in any safety, life support, or other hazard related device or system, and AKM assumes no responsibility relating to any such use, except with the express written consent of the Representative Director of AKM. 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