CS5360 24-Bit Stereo A/D Converter for Digital Audio Features Description l 24 The CS5360 is a 2-channel, single +5 V supply, 24-bit analog-to-digital converter for digital audio systems. The CS5360 performs sampling, analog-to-digital conversion and anti-alias filtering, generating 24-bit values for both left and right inputs in serial form. The output word rate can be up to 50 kHz per channel. Bit Conversion l 105 dB Dynamic Range l -95 dB THD+N l 128X Oversampling l Fully Differential Inputs l Linear Phase Digital Anti-Alias Filtering The CS5360 uses 4th-order, delta-sigma modulation with 128X oversampling followed by digital filtering and decimation, which removes the need for an external antialias filter. This ADC uses a differential architecture which provides excellent noise rejection. – 21.7 kHz passband (Fs = 48kHz) – 85 dB stop band attenuation – 0.0025 dB pass band ripple l High Pass Filter - DC Offset Removal l Peak Signal Level Detector The CS5360 has a filter passband to 21.7 kHz. The filter has linear phase, 0.0025 dB passband ripple, and >85 dB stopband rejection. An on-chip high pass filter is also included to remove DC offsets. – High Resolution and Bar Graph Modes l Pin Compatible with CS5334 and CS5335 ORDERING INFORMATION CS5360-KS -10° to 70°C CS5360-BS -40° to 85°C 20-pin Plastic SSOP 20-pin Plastic SSOP I CMOUT VA+ VD+ RST MCLK OVFL 3 6 18 7 2 FRAME 10 SCLK LRCK 8 12 15 Voltage Reference 9 Serial Output Interface 20 19 AINLAINL+ 16 + LP Filter 17 - + - S/H AINR+ High Pass Filter Digital Decimation Filter High Pass Filter 1 14 + 13 LP Filter - + - S/H DAC 5 11 AGND DGND PU P.O. Box 17847, Austin, Texas 78760 (512) 445 7222 FAX: (512) 445 7581 http://www.cirrus.com DIF1 Comparator 4 Preliminary Product Information DIF0 Comparator DAC AINR- Digital Decimation Filter SDATA HP DEFEAT This document contains information for a new product. Cirrus Logic reserves the right to modify this product without notice. Copyright Cirrus Logic, Inc. 1999 (All Rights Reserved) OCT ‘99 DS280PP2 1 CS5360 TABLE OF CONTENTS 1. CHARACTERISTICS AND SPECIFICATIONS ........................................................................ 3 ANALOG CHARACTERISTICS ................................................................................................ 3 DIGITAL FILTER CHARACTERISTICS.................................................................................... 4 DIGITAL CHARACTERISTICS ................................................................................................. 4 ABSOLUTE MAXIMUM RATINGS ........................................................................................... 4 SWITCHING CHARACTERISTICS .......................................................................................... 5 2. SYSTEM DESIGN ..................................................................................................................... 8 2.1 Master Clock ...................................................................................................................... 8 3. SERIAL DATA INTERFACE ..................................................................................................... 8 3.1 Serial Data ......................................................................................................................... 8 3.2 Serial Clock ........................................................................................................................ 8 3.3 Left / Right Clock .............................................................................................................. 10 3.4 Master Mode .................................................................................................................... 10 3.5 Slave Mode ...................................................................................................................... 10 3.6 Analog Connections ......................................................................................................... 10 3.7 High Pass Filter ................................................................................................................ 10 4. INPUT LEVEL MONITORING ................................................................................................. 11 4.1 High Resolution Mode ...................................................................................................... 11 4.2 Bar Graph Mode .............................................................................................................. 12 4.3 Overflow ........................................................................................................................... 12 4.4 Initialization ...................................................................................................................... 12 4.5 Initialization with High Pass Filter Enabled ...................................................................... 12 4.6 Initialization and Internal Calibration with High Pass Filter Disabled ............................... 12 4.7 Power-Down .................................................................................................................... 13 4.8 Grounding and Power Supply Decoupling ....................................................................... 13 4.9 Digital Filter ...................................................................................................................... 13 5. PIN DESCRIPTIONS .............................................................................................................. 15 6. PARAMETER DEFINITIONS .................................................................................................. 18 7. PACKAGE DIMENSIONS ....................................................................................................... 19 LIST OF FIGURES Figure 1. SCLK to SDATA & LRCK - MASTER Mode Format 0 and 1 ........................................... 6 Figure 3. SCLK to LRCK & SDATA - SLAVE Mode Format 0 & 1 .................................................. 6 Figure 2. SCLK to SDATA & LRCK - MASTER Mode Format 2 ..................................................... 6 Figure 4. SCLK to LRCK & SDATA - SLAVE Mode Format 2......................................................... 6 Figure 5. SCLK to Frame Delay ...................................................................................................... 6 Contacting Cirrus Logic Support For a complete listing of Direct Sales, Distributor, and Sales Representative contacts, visit the Cirrus Logic web site at: http://www.cirrus.com/corporate/contacts/ Preliminary product information describes products which are in production, but for which full characterization data is not yet available. Advance product information describes products which are in development and subject to development changes. Cirrus Logic, Inc. has made best efforts to ensure that the information contained in this document is accurate and reliable. However, the information is subject to change without notice and is provided “AS IS” without warranty of any kind (express or implied). No responsibility is assumed by Cirrus Logic, Inc. for the use of this information, nor for infringements of patents or other rights of third parties. This document is the property of Cirrus Logic, Inc. and implies no license under patents, copyrights, trademarks, or trade secrets. No part of this publication may be copied, reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photographic, or otherwise) without the prior written consent of Cirrus Logic, Inc. Items from any Cirrus Logic website or disk may be printed for use by the user. However, no part of the printout or electronic files may be copied, reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photographic, or otherwise) without the prior written consent of Cirrus Logic, Inc.Furthermore, no part of this publication may be used as a basis for manufacture or sale of any items without the prior written consent of Cirrus Logic, Inc. The names of products of Cirrus Logic, Inc. or other vendors and suppliers appearing in this document may be trademarks or service marks of their respective owners which may be registered in some jurisdictions. A list of Cirrus Logic, Inc. trademarks and service marks can be found at http://www.cirrus.com. 2 DS280PP2 CS5360 Figure 6. Typical Connection Diagram............................................................................................ 7 Figure 7. Data Block and Frame ..................................................................................................... 8 Figure 8. Serial Data Format 0........................................................................................................ 9 Figure 9. Serial Data Format 1........................................................................................................ 9 Figure 10. Serial Data Format 2...................................................................................................... 9 Figure 11. Full Scale Input Levels................................................................................................. 10 Figure 12. CS5360 Digital Filter Passband Ripple........................................................................ 14 Figure 13. CS5360 Digital Filter Transition Band.......................................................................... 14 Figure 14. CS5360 Digital Filter Stopband Rejection.................................................................... 14 Figure 15. CS5360 Digital Filter Transition Band.......................................................................... 14 LIST OF TABLES Table 1. Common Clock Frequencies............................................................................................. 9 Table 2. Digital Input Formats ......................................................................................................... 9 Table 3. Peak Signal Level Bits - High Resolution Mode.............................................................. 12 Table 4. P7 to P0 - Peak Signal Level Bits -Bar Graph Mode....................................................... 13 DS280PP2 3 CS5360 1. CHARACTERISTICS AND SPECIFICATIONS ANALOG CHARACTERISTICS (TA = 25 °C; VA+ = VD+ = 5 V; -1 dB Input sinewave, 997 Hz; Fs = 48 kHz; MCLK = 12.288 MHz; SCLK = 3.072 MHz; Measurement Bandwidth is 10 Hz to 20 kHz unless otherwise specified; Logic 0 = 0 V, Logic 1 = VD+) 5360-KS Parameter Symbol Temperature Range Min Min Typ Max -40 to +85 Units °C 100 97 105 102 - 95 92 105 102 - dB Total Harmonic Distortion + Noise (Note 1) THD+N -1 dB -20 dB -60 dB - -95 -82 -42 -90 -77 -37 - -95 -82 -42 -85 -72 -32 dB dB dB Interchannel Phase Deviation - 0.01 - - 0.01 - Degree - 105 - - 105 - dB - 0.05 - - 0.05 - dB - - ±5 - - ±5 % - 200 - - 200 - ppm/°C - 0 ±100 - - 0 ±100 - LSB LSB 1.9 2.0 2.1 1.9 2.0 2.1 Vrms - 30 - - 30 - kΩ - 2.2 - - 2.2 - V - 60 - - 60 - dB - 40 25 0.5 45 30 - - 40 25 0.5 45 30 - mA mA mA - 325 2.5 375 - - 325 2.5 375 - mW mW - 55 - - 55 - dB Interchannel Isolation A-weighted Max -10 to +70 TA Dynamic Performance Dynamic Range Typ 5360-BS (dc to 20 kHz) dc Accuracy Interchannel Gain Mismatch Gain Error Gain Drift Offset Error with HPF HP defeat with CAL Analog Input Input Voltage Range (Differential) VIN Input Impedance ZIN Input Bias Voltage Common Mode Rejection Ratio CMRR Power Supplies Power Supply Current IA ID Power Down (IA + ID) Power Dissipation Normal Power Down Power Supply Rejection Ratio Notes: 1. Referenced to nominal input level. Specifications are subject to change without notice 4 DS280PP2 CS5360 DIGITAL FILTER CHARACTERISTICS (Note 2, TA = 25 °C; VA+ = VD+ = 5 V ±5%; Fs = 48 kHz) Parameter Passband Symbol (Note 3) Min Typ Max Unit 0.02 - 21.7 kHz - - ±0.0025 dB Passband Ripple Stopband (Note 3) 26.3 - 6118 kHz Stopband Attenuation (Note 4) 85 - - dB tgd - 32/Fs - s ∆tgd - - 0 µs (Note 3) - 0.9 20 - Hz (Note 3) - 2.6 - Degree - - 0 dB Group Delay (Fs = Output Sample Rate) Group Delay Variation vs. Frequency High Pass Filter Characteristics Frequency Response -3 dB -0.1 dB Phase Deviation @20 Hz Passband Ripple Notes: 2. Filter response is not tested but is guaranteed by design. 3. Filter characteristics scale with output sample rate. 4. The analog modulator samples the input at 6.144 MHz for an output sample rate of 48 kHz. There is no rejection of input signals which are multiples of the sampling frequency (n x 6.144 MHz ±21.7 kHz where n = 0, 1, 2, 3, ...). DIGITAL CHARACTERISTICS (TA = 25 °C; VA+ = VD+ = 5 V ±5%) Parameter Symbol Min Max Unit High-level Input Voltage VIH 2.4 - V Low-level Input Voltage VIL - 0.8 V High-level Output Voltage at Io = -20 µA VOH (VD+) - 1.0 - V Low-level Output Voltage at Io = 20 µA VOL - 0.4 V Iin - 10 µA Input Leakage Current ABSOLUTE MAXIMUM RATINGS (AGND = 0 V, all voltages with respect to ground.) Parameter DC Power Supply Symbol Min Max Unit VA+ -0.3 +6.0 V Iin - ±10 mA Input Current, Any Pin Except Supplies (Note 5) Analog Input Voltage (Note 6) VINA -0.7 (VA+) + 0.7 V Digital Input Voltage (Note 6) VIND -0.7 (VA+) + 0.7 V Ambient Temperature (power applied) TA -55 +125 °C Storage Temperature Tstg -65 +150 °C Notes: 5. Any pin except supplies. Transient currents of up to ±100 mA on the analog input pins will not cause SCR latch-up. 6. The maximum over/under voltage is limited by the input extremes. WARNING: Operation at or beyond these limits may result in permanent damage to the device. Normal operation is not guaranteed at these extremes. DS280PP2 5 CS5360 SWITCHING CHARACTERISTICS (TA = 25 °C; VA+ = 5 V ±5%; Inputs: Logic 0 = 0 V, Logic 1 = VA+ = VD+; CL = 20 pF) Parameter Output Sample Rate Symbol Min Typ Max Unit FS 8.0 - 50 kHz MCLK Period MCLK / LRCK = 256 MCLK / LRCK = 384 MCLK / LRCK = 512 tclkw 78 52 39 - 1953 1302 976 ns MCLK Low MCLK / LRCK = 256 MCLK / LRCK = 384 MCLK / LRCK = 512 tclkl 31 20 15 - - ns MCLK High MCLK / LRCK = 256 MCLK / LRCK = 384 MCLK / LRCK = 512 tclkh 31 20 15 - - ns pupulse 20 - - ns (Note 7) tmslr -10 - 10 ns (Note 7) tsdo -10 - 35 ns - 50 - % (Note 7) tsfo -10 - Note 8 ns tovfl -10 - 30 ns tovfl -10 - Note 12 ns 25 50 75 % tsclkw Note 9 - - ns (Note 10) tsclkl Note 13 - - ns (Note 11) tsclkh 50 - - ns (Note 7) tdss - - Note 13 ns tlrdss - - Note 13 ns (Note 14) tslr1 50 - - ns (Note 14) tslr2 Note 13 - - ns tsfo - - Note 15 ns Peak Update Pulse Width Master Mode SCLK Falling to LRCK SCLK Falling to SDATA Valid SCLK Duty Cycle SCLK Falling to Frame Valid LRCK Edge to OVFL Valid LRCK Edge to OVFL Edge Delay Slave Mode LRCK Duty Cycle SCLK Period SCLK Pulse Width Low SCLK Pulse Width High SCLK Falling to SDATA Valid LRCK Edge to MSB Valid SCLK Rising to LRCK Edge Delay LRCK Edge to Rising SCLK Setup Time SCLK Falling to Frame Delay Notes: 7. SCLK Rising for Mode 1 1 - + 30 ns 8. -----------------------------( 1024 ) ( F ) S 9. 1 -----------------------( 96 ) ( F ) S 10. Pulse Width High for Mode 1 11. Pulse Width Low for Mode 1 1 12. --------------------------- + 20 ns ( 512 ) ( F ) 13. S 1 ---------------------------- + 50 ns ( 512 ) ( F ) S 14. SCLK Falling for Mode 1 15. 6 1 ---------------------------- + 35 ns ( 384 ) ( F ) S DS280PP2 CS5360 SCLK output SCLK output* t mslr t mslr LRCK output LRCK output t sdo t sdo MSB SDATA MSB-1 SDATA MSB t ovfl t ovfl OVFL OVFL Figure 1. SCLK to SDATA & LRCK - MASTER Mode Format 0 and 1 t slr1 t slr2 Figure 2. SCLK to SDATA & LRCK - MASTER Mode Format 2 t sclkl t sclkh t slr1 t slr2 SCLK input* (SLAVE mode) t sclkl t sclkh SCLK input (SLAVE mode) t sclkw LRCK input (SLAVE mode) t sclkw LRCK input (SLAVE mode) t lrdss MSB SDATA t dss MSB-1 MSB-2 t dss SDATA t ovfl OVFL MSB MSB-1 t ovfl OVFL Figure 3. SCLK to LRCK & SDATA - SLAVE Mode Format 0 & 1 Figure 4. SCLK to LRCK & SDATA - SLAVE Mode Format 2 SCLK* t sfo FRAME Figure 5. SCLK to Frame Delay * SCLK is inverted in Format 1 DS280PP2 7 CS5360 2Ω +5V Analog + 0.1 µF 1 µF 0.1 µF 6 VD+ Left Analog Input + Left Analog Input - 3 VA+ CS5360 150 Ω 17 2.2 nF 150 Ω 16 OVFL PU AINL- Right Analog Input + Right Analog Input - DIF0 DIF1 SDATA 150 Ω 13 2.2 nF 150 Ω CMOUT 14 AINR+ AINR- LRCK SCLK MCLK RST FRAME * Required for Master Mode only ** Required for Bar Graph Mode only 2 * 47 kΩ AINL+ HP DEFEAT 15 1 µF + Peak Signal Level Monitor 11 1 20 Mode Settings 19 9 12 8 7 100 Ω 100 Ω Audio Data Processing 100 Ω 100 Ω 18 10 Timing, Logic & Clock ** 47 kΩ DGND 5 AGND 4 Figure 6. Typical Connection Diagram 8 DS280PP2 CS5360 2. SYSTEM DESIGN 3. SERIAL DATA INTERFACE The CS5360 is a 24-bit, 2-channel analog-to-digital converter designed for digital audio applications. This device uses two one-bit delta-sigma modulators which simultaneously sample the analog input signals at 128 times the output sample rate (Fs). The resulting serial bit streams are digitally filtered, yielding a pair of 24-bit values. This technique yields nearly ideal conversion performance independent of input frequency and amplitude. The converter does not require difficult-to-design or expensive anti-alias filters and does not require external sample-and-hold amplifiers or a voltage reference. Very few external components are required to support this ADC. Normal power supply decoupling components and a resistor and capacitor on each input for anti-aliasing are the only external components required, as shown in Figure 6. The CS5360 supports three serial data formats, including I2S, selected via the digital interface format pins DIF0 and DIF1. The digital interface format determines the relationship between the serial data, left/right clock and serial clock. Table 2 lists the three formats and their associated figure number. The serial data interface is accomplished via the serial data output, SDATA, serial data clock, SCLK, and the left/right clock, LRCK. An on-chip voltage reference provides for a differential input signal range of 2.0 Vrms. Output data is available in serial form, coded as 2’scomplement, 24-bit numbers. Typical power consumption is 325 mW which can be reduced to 1.0 mW by using the power-down feature. The serial data block consists of 24 bits of audio data presented in 2’s-complement format with the MSB-first followed by 8 Peak Signal Level, PSL, bits as shown in Figure 7. The data is clocked from SDATA by the serial clock and the channel is determined by the Left/Right clock. 2.1 DIF1 0 0 1 1 LRCK (kHz) 256 X 8.1920 11.2896 12.2880 32 44.1 48 MCLK (MHz) 384 X 12.2880 16.9344 18.4320 3.1 Table 1. Common Clock Frequencies DS280PP2 FIGURE 8 9 10 - Serial Data 24 Audio Data Bits SDATA 23 22 21 20 19 18 8 PSL Bits 1 0 P7 P6 P1 P0 FRAME Figure 7. Data Block and Frame 3.2 512 X 16.3840 22.5792 24.5760 FORMAT 0 1 2 power-down Table 2. Digital Input Formats Master Clock The master clock (MCLK) is the clock source for the delta-sigma modulator and digital filters. In Master Mode, the frequency of this clock must be 256x Fs. In SlaveMode, the master clock must be either 256x, 384x or 512x Fs. Table 1 shows some common master clock frequencies. DIF0 0 1 0 1 Serial Clock The serial clock shifts the digital audio data from the internal data registers via the SDATA pin. SCLK is an output in Master Mode. Internal dividers will divide the master clock by 4 to generate a serial clock which is 64x Fs. In Slave Mode, SCLK is an input with a serial clock typically between 48x and 96x Fs. However, the serial clock must be a minimum of 64x Fs to access the Peak Signal Level bits. 9 CS5360 LEFT LRCK RIGHT (64X) SCLK SDATA P0 23 22 21 20 19 18 5 4 3 2 1 0 P7 P6 P5 P4 P3 P2 P1 P0 23 22 21 20 19 18 5 4 3 2 1 0 P7 P6 P5 P4 P3 P2 P1 P0 23 22 FRAME MASTER 24-Bit Left Justified Data Data Valid on Rising Edge of 64x SCLK MCLK equal to 256x Fs SLAVE 24-Bit Left Justified Data Data Valid on Rising Edge of SCLK MCLK equal to 256x, 384x, or 512x Fs Figure 8. Serial Data Format 0 LRCK LEFT RIGHT (64X) SCLK SDATA P0 23 22 21 20 19 18 5 4 3 2 1 0 P7 P6 P5 P4 P3 P2 P1 P0 23 22 21 20 19 18 5 4 3 2 1 0 P7 P6 P5 P4 P3 P2 P1 P0 23 22 1 0 P7 P6 P5 P4 P3 P2 P1 P0 23 22 FRAME MASTER d Data ng Edge of 64x SCLK 6x Fs SLAVE 24-Bit Left Justified Data Data Valid on Falling Edge of SCLK MCLK equal to 256x, 384x, or 512x Fs Figure 9. Serial Data Format 1 LRCK LEFT RIGHT (64X) SCLK SDATA P0 23 22 21 20 19 18 5 4 3 2 1 0 P7 P6 P5 P4 P3 P2 P1 P0 23 22 21 20 19 18 5 4 3 2 FRAME MASTER 2 SLAVE I S 24-Bit Left Justified Data Data Valid on Rising Edge of 64x SCLK MCLK equal to 256x Fs 2 I S 24-Bit Left Justified Data Data Valid on Rising Edge of SCLK MCLK equal to 256x, 384x, or 512x Fs Figure 10. Serial Data Format 2 10 DS280PP2 CS5360 3.3 Left / Right Clock The Left/Right clock determines which channel, left or right, is to be output on SDATA. Although the outputs for each channel are transmitted at different times, Left/Right pairs represent simultaneously sampled analog inputs. In Master Mode, LRCK is an output whose frequency is equal to Fs. In Slave Mode, LRCK is an input whose frequency must be equal to the output sample rate, Fs. 3.4 Master Mode In Master mode, SCLK and LRCK are outputs which are internally derived from the Master Clock. Internal dividers will divide MCLK by 4 to generate a SCLK which is 64x Fs and by 256 to generate a LRCK which is equal to Fs. Master mode is only supported with a 256x master clock. The CS5360 is placed in the Master mode with a 47 kΩ pull-down resistor on the OVFL pin. 3.5 Slave Mode LRCK and SCLK become inputs in SLAVE mode. LRCK must be externally derived from MCLK and be equal to Fs. The serial clock is typically between 64x and 96x Fs. A 48x Fs serial clock is possible though will not allow access to the Peak Signal Level bits. Master clock frequencies of 256x, 384x and 512x Fs are supported. The ratio of the applied master clock to the left/right clock is automatically detected during power-up and internal dividers are set to generate the appropriate internal clocks. 3.6 Analog Connections Figure 6 shows the analog input connections. The analog inputs are presented to the modulators via the AINR+/- and AINL+/- pins. Each analog input pin will accept a maximum of 1Vrms centered at +2.2 Volt as shown in Figure 11. Input signals can be AC or DC coupled and the CMOUT output may be used as a reference for DC coupling. However, CMOUT is not buffered, and the maximum current is 10 µA. DS280PP2 CS5360 3.6 V 2.2 V AIN+ 0.78 V 3.6 V 2.2 V AIN- 0.78 V Full Scale Input level= (AIN+) - (AIN-)= 5.67 Vpp Figure 11. Full Scale Input Levels The CS5360 samples the analog inputs at 128x Fs, 6.144MHz for a 48kHz sample-rate. The digital filter rejects all noise above 26.3kHz except for frequencies right around 6.144MHz ±21.7kHz (and multiples of 6.144MHz). Most audio signals do not have significant energy at 6.144MHz. Nevertheless, a 150 Ω resistor in series with each analog input and a 2.2 nF capacitor across the inputs will attenuate any noise energy at 6.144MHz, in addition to providing the optimum source impedance for the modulators. The use of capacitors which have a large voltage coefficient must be avoided since these will degrade signal linearity. NPO and COG capacitors are acceptable. If active circuitry precedes the ADC, it is recommended that the above RC filter is placed between the active circuitry and the AINR and AINL pins. The above example frequencies scale linearly with the sample rate. 3.7 High Pass Filter The operational amplifiers in the input circuitry driving the CS5360 may generate a small DC offset into the A/D converter. The CS5360 includes a high pass filter after the decimator to remove any DC offset which could result in recording a DC level, possibly yielding "clicks" when switching between devices in a multichannel system. The high pass filter can be disabled with the HP DEFEAT pin. The high pass filter works by continuously subtracting a measure of the dc offset from the output of the decimation filter. If the HP DEFEAT pin is 11 CS5360 taken high during normal operation, the current value of the dc offset register is frozen and this dc offset will continue to be subtracted from the conversion result. This feature makes it possible to perform a system calibration by: 1) removing the signal source (or grounding the input signal) at the input to the subsystem containing the CS5360, 2) running the CS5360 with the HP DEFEAT pin low (high pass filter enabled) until the filter settles (approximately 1 second), and 3) taking the HP DEFEAT pin high, disabling the high pass filter and freezing the stored dc offset. A system calibration performed in this way will eliminate offsets anywhere in the signal path between the calibration point and the CS5360. The characteristics of the first-order high pass filter are outlined below for an output sample rate of 48 kHz. This filter response scales linearly with sample rate. Frequency response: -3 dB @ 0.9 Hz -0.01 dB @ 20 Hz Phase deviation: 2.6 degrees @ 20 Hz Passband ripple: None 4. INPUT LEVEL MONITORING The CS5360 includes independent Peak Input Level Monitoring for each channel. The analog-to-digital converter continually monitors the peak digital signal for both channels, prior to the digital limiter, and records these values in the Active registers. This information can be transferred to the Output registers by a high to low transition on the Peak Update pin (PU) which will also reset the Active register. The Active register contains the peak signal level since the previous peak update request. The 8-bit contents of the output registers are available in all interface modes and are present in the data block as shown in Figure 7. The monitoring 12 function can be formatted to indicate either High Resolution Mode or Bar Graph Mode. The monitoring function is determined on power-up by the presence of a 47 kΩ pull-down resistor on FRAME. The addition of a 47 kΩ pull-down resistor on the FRAME pin sets the monitoring function to the Bar Graph mode. 4.1 High Resolution Mode Bits P7-P0 indicate the peak input level since the previous peak update (or low transition on the Peak Update pin). If the full scale input level is exceeded (Bit P7 high), bits P5-P0 represent the peak value up to 3 dB above full-scale in 1 dB steps. If the ADC input level is less than full-scale, bits P5-P0 represent the peak value from -60 dB to 0 dB of full scale in 1 dB steps. The PSL outputs are accurate to within 0.25 dB. Bit P6 provides a coarse means of determining an ADC input idle condition. Bit P7 indicates an ADC overflow condition, if the ADC input level is greater than full-scale. P7 - Overrange 0 - Analog input less than full-scale level 1 - Analog input greater than full-scale P6 - Idle channel 0 - Analog input >-60 dB from full-scale 1 - Analog input <-60 dB from full-scale P5 to P0 - Peak Signal Level Bits (1 dB steps) Inputs <0 dB P5 - P0 0 dB 000000 -1 dB 000001 -2 dB 000010 -60 dB 111100 Inputs >0 dB P5 - P0 0 dB 000000 +1 dB 000001 +2 dB 000010 +3 dB 000011 Table 3. Peak Signal Level Bits - High Resolution Mode DS280PP2 CS5360 4.2 Bar Graph Mode This mode provides a decoded output format which indicates the peak Peak Signal Level in a "Bar Graph" format. Input Level P7 - P0 Overflow 11111111 0 dB to -3 dB 01111111 -3 dB to -6 dB 00111111 -6 dB to -10 dB 00011111 -10 dB to -20 dB 00001111 -20 dB to -30 dB 00000111 -30 dB to -40 dB 00000011 -40 dB to -60 dB 00000001 < - 60 dB 00000000 Table 4. P7 to P0 - Peak Signal Level Bits -Bar Graph Mode 4.3 Overflow Overflow indicates analog input overrange for the Left and Right channels as of the last update request on the Peak Update pin. A value of 1 indicates an overrange condition. The left channel information is output on OVFL during the left channel portion of LRCK. The right channel information is available on OVFL during the right channel portion of LRCK. 4.4 Initialization Upon initial power-up, the digital filters and deltasigma modulators are reset and the internal voltage reference is powered down. The CS5360 will remain in the power-down mode until valid clocks are presented. A valid MCLK is required to exit power-down in Master Mode. However, in Slave Mode, MCLK and LRCK of the proper ratio are required to exit power-down. MCLK occurrences are also counted over one LRCK period to determine DS280PP2 the MCLK / LRCK frequency ratio in Slave Mode. Power is then applied to the internal voltage reference, the analog inputs will move to approximately 2.2 V and output clocks will begin (Master Mode only). This process requires 32 periods of LRCK and is followed by the initialization sequence. 4.5 Initialization with High Pass Filter Enabled 28,672 LRCK cycles are required for the initialization sequence with the high pass filter enabled. This time is dominated by the settling time required for the high pass filter. 4.6 Initialization and Internal Calibration with High Pass Filter Disabled If the HP DEFEAT pin is high (high pass filter disabled) during the initialization sequence, the CS5360 will perform an internal dc calibration by: 1) disconnecting the internal ADC inputs from the input pins, 2) connecting the (differential) ADC inputs to a common reference voltage, 3) running the high pass filter with a fast settling time constant, 4) freezing the dc offset register, and 5) reconnecting the internal ADC inputs to the input pins. This procedure takes 4,160 cycles of LRCK. Unlike the system calibration procedure described in the High Pass Filter section, a dc calibration performed during start-up will only eliminate offsets internal to the CS5360, and should result in output codes which accurately reflect the differential dc signal at the pins. 13 CS5360 4.7 Power-Down The CS5360 has a power-down mode wherein typical consumption drops to 1.0 mW. This is initiated when a loss of clock is detected (either LRCK or MCLK in Slave Mode or MCLK in Master Mode), RST is enabled or DIF0 / DIF1 are at a logic 1. The initialization sequence will begin whenever valid clocks are restored, RST is disabled and DIF0 / DIF1 are restored. If the MCLK / LRCK frequency ratio changes during power-down, the CS5360 will adapt to these new operating conditions. However, only the RST method of power-down will include the Master/Slave decision in the initialization sequence. 4.8 Grounding and Power Supply Decoupling As with any high resolution converter, the CS5360 requires careful attention to power supply and grounding arrangements to optimize performance. Figure6 shows the recommended power arrangements with VA+ connected to a clean +5volt supply. VD+ should be derived from VA+ through a 2 ohm resistor. VD+ should not be used to power additional digital circuitry. All mode pins which require VD+ should be connected to pin 6 of the CS5360. All mode pins which require DGND should be connected to pin 5 of the CS5360. AGND and DGND, Pins 4 and 5, should be connected together at the CS5360. DGND for the CS5360 should not be confused with the ground for 14 the digital section of the system. The CS5360 should be positioned over the analog ground plane near the digital / analog ground plane split. The analog and digital ground planes must be connected elsewhere in the system. The CS5360 evaluation board, CDB5360, demonstrates this layout technique. This technique minimizes digital noise and insures proper power supply matching and sequencing. Decoupling capacitors should be located as near to the CS5360 as possible. 4.9 Digital Filter Figures 12-15 show the performance of the digital filter included in the CS5360. All plots are normalized to Fs. Assuming a sample rate of 48 kHz, the 0.5 frequency point on the plot refers to 24 kHz. The filter frequency response scales precisely with the sample rate. DS280PP2 CS5360 Figure 12. CS5360 Digital Filter Passband Ripple Figure 13. CS5360 Digital Filter Transition Band Figure 14. CS5360 Digital Filter Stopband Rejection Figure 15. CS5360 Digital Filter Transition Band DS280PP2 15 CS5360 5. PIN DESCRIPTIONS High Pass Filter Defeat HPDEFEAT 1 20 DIF0 Digital Interface Format 0 Overflow OVFL 2 19 DIF1 Digital Interface Format 1 Analog Power VA+ 3 18 RST Reset Analog Ground AGND 4 17 AINL+ Non-Inverting Left Channel Input Digital Ground DGND 5 16 AINL- Inverting Left Channel Input Digital Power VD+ 6 15 CMOUT Common Mode Output Master Clock MCLK 7 14 AINR- Inverting Right Channel Input Serial Data Clock SCLK 8 13 AINR+ Non-Inverting Right Channel Input Serial Data Output SDATA 9 12 LRCK Left / Right Clock Frame Signal FRAME 10 11 PU Peak Update High Pass Filter Defeat - HP DEFEAT Pin 1, Input Function A high logic level on this pin disables the digital high pass filter. A low logic level on this pin enables the high pass filter. Overflow - OVFL Pin 2, Input Function Overflow indicates analog input overrange, for both the Left and Right channels, since the last update request on the PEAK UPDATE (PU) pin. A value of 1 in the register indicates an overrange condition. The left channel information is output on OVFL during the left channel portion of LRCK. The right channel information is available on OVFL during the right channel portion of LRCK. The registers are updated with a high to low transition on the PEAK UPDATE pin. A 47 kΩ pull-down resistor on this pin will set the CS5360 in Master Mode. Positive Analog Power - VA+ Pin 3, Input Function: Positive analog supply. Nominally +5 volts. Analog Ground - AGND Pin 4, Input Function: Analog ground reference. DGND - Digital Ground Pin 5, Input Function: Digital ground reference. 16 DS280PP2 CS5360 Positive Digital Power - VD+ Pin 6, Input Function: Positive digital supply. Nominally +5 volts. Master Clock - MCLK Pin 7, Input Function: Clock source for the delta-sigma modulator sampling and digital filters. In Master Mode, the frequency of this clock must be 256x the output sample rate, Fs. In Slave Mode, the frequency of this clock must be either 256x, 384x or 512x Fs. Serial Data Clock - SCLK Pin 8, Input/Output Function: Clocks the individual bits of the serial data out from the SDATA pin. The relationship between LRCK, SCLK and SDATA is controlled by DIF0 and DIF1.In Master Mode, SCLK is an output clock with a frequency of 64x the output sample rate, Fs.In Slave Mode, SCLK is an input. Serial Data Output - SDATA Pin 9, Output Function: Two’s complement MSB-first serial data of 24 bits is output on this pin. Included in the serial data output is the 8-bit Input Signal Level Bits. The data is clocked out via the SCLK clock and the channel is determined by LRCK. The relationship between LRCK, SCLK and SDATA is controlled by DIF0 and DIF1. Peak Update - PU Pin 11, Input Function: Transfers the Peak Signal Level contents of the Active Registers to the Output Registers on a high to low transition on this pin. This transition will also reset the Active register. Frame Signal - FRAME Pin 10, Output Function: Frames the Peak Signal Level (PSL) Bits. FRAME goes high coincident with the leading edge of the first PSL bit and falls coincident with the trailing edge of the last PSL bit as shown in Figures 8-10. A 47 kΩ pull-down resistor on this pin will set the Peak Signal Level Monitoring format to "Bar Graph" mode. Left/Right Clock - LRCK Pin 12, Input/Output Function: LRCK determines which channel, left or right, is to be output on SDATA. The relationship between LRCK, SCLK and SDATA is controlled by DIF0 and DIF1. Although the outputs for each channel are transmitted at different times, Left/Right pairs represent simultaneously sampled analog inputs. In Master Mode, LRCK is an output clock whose frequency is equal to the output sample rate, Fs. In Slave Mode, LRCK is an input clock whose frequency must be equal to Fs. DS280PP2 17 CS5360 Differential Right Channel Analog Input - AINR+, AINR- Pin 13 and Pin 14, Input Function: Analog input connections of the right channel differential inputs. Typically 2 Vrms differential (1Vrms for each input pin) for a full-scale analog input signal. Common Mode Output - CMOUT Pin 15, Output Function: This output, nominally 2.2 V, can be used to bias the analog input circuitry to the common mode voltage of the CS5360. CMOUT is not buffered and the maximum current is 10 µA. Differential Left Channel Analog Input - AINL+, AINL- Pin 16 and Pin 17, Input Function: Analog input connections of the left channel differential inputs. Typically 2 Vrms differential (1Vrms for each input pin) for a full-scale analog input signal. Reset - RST Pin 18, Input Function: A low logic level on this pin activates Reset. Digital Interface Format - DIF0, DIF1 Pins 19 and 20, Input Function: These two pins select one of 3 digital interface formats or power-down. The format determines the relationship between SCLK, LRCK and SDATA. The formats are detailed in Figures 8-10. 18 DS280PP2 CS5360 6. PARAMETER DEFINITIONS Dynamic Range The ratio of the rms value of the signal to the rms sum of all other spectral components over the specified bandwidth. Dynamic Range is a signal-to-noise ratio measurement over the specified bandwidth made with a -60 dBFS signal. 60 dB is added to resulting measurement to refer the measurement to full-scale. This technique ensures that the distortion components are below the noise level and do not affect the measurement. This measurement technique has been accepted by the Audio Engineering Society, AES17-1991, and the Electronic Industries Association of Japan, EIAJ CP-307. Expressed in decibels. Total Harmonic Distortion + Noise (THD+N) The ratio of the rms value of the signal to the rms sum of all other spectral components over the specified band width (typically 10 Hz to 20 kHz), including distortion components. Expressed in decibels. Measured at -1 and -20 dBFS as suggested in AES17-1991 Annex A. Frequency Response A measure of the amplitude response variation from 10 Hz to 20 kHz relative to the amplitude response at 1 kHz. Units in decibels. Interchannel Isolation A measure of crosstalk between the left and right channels. Measured for each channel at the converter’s output with no signal at the input under test and a full-scale signal applied to the other channel. Units in decibels. Interchannel Gain Mismatch The gain difference between left and right channels. Units in decibels. Gain Error The deviation from the nominal full-scale analog input for a full-scale digital output. Gain Drift The change in gain value with temperature. Units in ppm/°C. Offset Error The deviation of the mid-scale transition (111...111 to 000...000) from the ideal. Units in mV. DS280PP2 19 CS5360 7. PACKAGE DIMENSIONS 20 PIN SSOP PACKAGE DRAWING N D E11 A2 E e A1 2 b A ∝ END VIEW L SIDE VIEW SEATING PLANE 1 2 3 TOP VIEW INCHES DIM A A1 A2 b D E E1 e L ∝ MIN -0.002 0.064 0.009 0.272 0.291 0.197 0.024 0.025 0° MILLIMETERS MAX 0.084 0.010 0.074 0.015 0.295 0.323 0.220 0.027 0.040 8° MIN -0.05 1.62 0.22 6.90 7.40 5.00 0.61 0.63 0° MAX 2.13 0.25 1.88 0.38 7.50 8.20 5.60 0.69 1.03 8° NOTE 2,3 1 1 Notes: 1. “D” and “E1” are reference datums and do not included mold flash or protrusions, but do include mold mismatch and are measured at the parting line, mold flash or protrusions shall not exceed 0.20 mm per side. 2. Dimension “b” does not include dambar protrusion/intrusion. Allowable dambar protrusion shall be 0.13 mm total in excess of “b” dimension at maximum material condition. Dambar intrusion shall not reduce dimension “b” by more than 0.07 mm at least material condition. 3. These dimensions apply to the flat section of the lead between 0.10 and 0.25 mm from lead tips. 20 DS280PP2 • Notes •