Ordering number : EN6123B LC72722PM CMOS IC Single-Chip RDS Signal-Processing System IC http://onsemi.com Overview The LC72722PM is a single-chip system IC that implement the signal processing required by the European Broadcasting Union RDS (Radio Data System) standard and by the US NRSC (National Radio System Committee) RBDS (Radio Broadcast Data System) standard. This IC include band-pass filter, demodulator, synchronization, and error correction circuits as well as data buffer RAM on chip and perform effective error correction using a soft-decision error correction technique. Functions • Band-pass filter : switched capacitor filter (SCF) • Demodulator : RDS data clock regeneration and demodulated data reliability information • Synchronization : Block synchronization detection (with variable backward and forward protection conditions) • Error correction : Soft-decision/hard-decision error correction • Buffer RAM : Adequate for 24 blocks of data (about 500ms) and flag memory • Data I/O : CCB interface (power on reset) Features • Error correction capability improved by soft-decision error correction • The load on the control microprocessor can be reduced by storing decoded data in the on-chip data buffer RAM. • Two synchronization detection circuits provide continuous and stable detection of the synchronization. • Data can be read out starting with the backward-protection block data after a synchronization reset. • Fully adjustment free Specifications • Operating power-supply voltage : • Operating temperature : • Package : 4.5 to 5.5V -40 to +85°C MFP24(375mil) • CCB is ON Semiconductor® ’s original format. All addresses are managed by ON Semiconductor® for this format. • CCB is a registered trademark of Semiconductor Components Industries, LLC. Semiconductor Components Industries, LLC, 2013 June, 2013 60612HK B8-9103,8341/51202AS(OT)/83199TH(OT) No. 6123-1/18 LC72722PM Specifications Absolute Maximum Ratings at Ta = 25°C, Vssd = Vssa = 0V Parameter Symbol Maximum supply voltage Maximum input voltage Maximum output voltage Maximum output current Allowable power dissipation Pin Name Ratings Unit Vddmax Vddd, Vdda -0.3 to +7.0 V Vin1max CL, DI, CE, SYR, T1, T2, T3, T4, T5, T6, T7, SYNC -0.3 to +7.0 V Vin2max XIN -0.3 to Vddd+0.3 V Vin3max MPXIN, CIN -0.3 to Vdda+0.3 V Vo1max DO, SYNC, RDS-ID, T3, T4, T5, T6, T7 -0.3 to +7.0 V Vo2max XOUT -0.3 to Vddd+0.3 V Vo3max FLOUT -0.3 to Vdda+0.3 V Io1max DO, T3, T4, T5, T6, T7 +6.0 mA Io2max XOUT, FLOUT +3.0 mA Io3max SYNC, RDS-ID +20.0 mA Pdmax (Ta≤85°C) 175 mW Operating temperature Topr -40 to +85 °C Storage temperature Tstg -55 to +125 °C Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. Allowable Operating Ranges at Ta = -40 to 85°C, Vssd = Vssa = 0V Parameter Pin Name Symbol Vdd1 Vddd, Vdda Vdd2 Vddd Conditions Ratings min typ max 4.5 5.0 5.5 Unit V Supply voltage Input high-level voltage Input low-level voltage Output voltage VIH VIL VO VIN1 Input amplitude Guaranteed crystal CL, DI, CE, SYR, T1, T2 CL, DI, CE, SYR, T1, T2 V 0.7Vddd 6.5 V 0 0.3Vddd V 6.5 V 50 mVrms T4, T5, T6, T7 MPXIN f=57±2kHz 100% modulation composite VIN2 VXIN XIN XTAL XIN, XOUT TXtal 2.0 DO, SYNC, RDS-ID, T3, Oscillator frequencies Crystal oscillator frequency deviation Serial data hold voltage XIN, XOUT 100 mVrms 400 1500 mVrms CI≤120Ω (XS=0) 4.332 MHz CI≤70Ω (XS=1) 8.664 MHz ±100 fo=4.332MHz, 8.664MHz ppm Data setup time tSU DI, CL 0.75 μs Data hold time tHD DI, CL 0.75 μs Clock low level time tCL CL 0.75 μs Clock high level time tCH CL 0.75 μs CE wait time tEL CE, CL 0.75 μs CE setup time tES CE, CL 0.75 μs 0.75 CE hold time tEH CE, CL CE high-level time tCE CE Data latch change tLC μs 20 ms 1.15 μs 0.46 μs 0.46 μs time tDC DO,CL tDH DO,CE Data output time Differs depending on the value of the pull-up resistor used. No. 6123-2/18 LC72722PM Electrical Characteristics at Ta = -40 to 85°C, Vssd = Vssa = 0V Parameter Pin Name Symbol RMPXIN Conditions Ratings min typ max Unit MPXIN-Vssa f=57kHz 43.0 kΩ CIN-Vssa f=57kHz 100.0 kΩ 1.0 MΩ Input resistance Rcin Internal feedback Rf XIN Center frequency fc FLOUT 56.5 57.0 57.5 kHz -3dB band width BW-3dB FLOUT 2.5 3.0 3.5 kHz 31 34 dB resistance Gain Gain MPXIN-FLOUT f=57kHz 28 Att1 FLOUT Δf=±7kHz 30 dB Att2 FLOUT f<45kHz, f>70kHz 40 dB Att3 FLOUT f<20kHz 50 dB Vref Vref Vdda=5.0V Hysteresis VHIS CL, DI, CE, SYR, T1, T2 Output low-level VOL1 DO, T3, T4, T5, T6, T7 I=2mA 0.5 voltage VOL2 Stop band Attenuation Reference voltage 2.5 V 0.1Vddd V output V SYNC, RDS-ID I=8mA 0.5 V Input high-level IIH1 CL, DI, CE, SYR, T1, T2 VI= Vddd 5.0 μA current IIH2 XIN VI=Vddd 11.0 μA Input low-level IIL1 CL, DI, CE, SYR, T1, T2 VI=0V 5.0 μA current IIL2 XIN VI=0V 11.0 μA DO, SYNC, RDS-ID, T3, VO=6.5V 5.0 μA Output off leakage IOFF current Current drain 2.0 2.0 T4, T5, T6, T7 Idd Vddd, Vdda 9 mA No. 6123-3/18 LC72722PM Package Dimensions unit:mm 3045C 15.2 13 0.65 7.9 10.5 24 1 1.27 0.35 12 0.15 0.1 (2.15) 2.35max (0.62) SANYO : MFP24(375mil) Pin Assignment 24 SYR VREF 1 23 CE MPXIN 2 Vdda 3 22 DI Vssa 4 21 CL FLOUT 5 20 DO CIN 6 LC72722PM 19 RDS-ID T1 7 18 SYNC T2 8 17 T7 (CORREC/ARI-ID/TA/BEO) T3 (RDCL) 9 16 T6 (ERROR/57K/TP/BE1) T4 (RDDA) 10 15 Vssd T5 (RSFT) 11 14 Vddd 13 XIN XOUT 12 Top view No. 6123-4/18 LC72722PM Block Diagram +5.0V VREF FLOUT Vdda Vssa MPXIN DO CL DI CE + REFERENCE VOLTAGE ANTIALIASING FILTER CCB +5.0V CIN PLL (57kHz) VREF 57kHz BPF (SCF) SMOOTHING FILTER RAM (24 BLOCK DATA) CLOCK RECOVERY (1187.5Hz) DATA DECODER ERROR CORRECTION (SOFT DECISION) SYNC/EC CONTROLLER Vddd Vssd RDS-ID SYNC SYR CLK (4.332MHz) T1 T2 T3 to T7 TEST MEMORY CONTROL OSC/DIVIDER XIN SYNC DETECT-1 SYNC DETECT-2 XOUT No. 6123-5/18 LC72722PM Pin Functions Pin No. Pin name Function I/O Pin circuit Vdda 1 VREF Reference voltage output (Vdda/2) Output Vssa Vdda 2 MPXIN Baseband (multiplexed) signal input Input Vssa 5 FLOUT Subcarrier output (filter output) Output Vdda 7 CIN Subcarrier input (comparator input) Input Vssa VREF 3 Vdda Analog system power supply (+5V) − − 4 Vssa Analog system ground − − 12 XOUT Crystal oscillator output (4.332/8.664MHz) Vddd Output XIN 13 XIN Crystal oscillator input (external reference signal input) 7 T1 Test input (This pin must always be connected to ground.) XOUT Input S Test input (standby control) 8 T2 Vssd Vssd 0:Normal operation, 1:Standby state (crystal oscillator stopped) 9 T3(RDCL) Test I/O (RDS clock output) 10 T4(RDDA) Test I/O (RDS data output) 11 T5(RSFT) Test I/O (soft-decision control data output) T6 16 (ERROR/57K/BE1) Test I/O (error status, regenerated carrier, error block count) T7 Test I/O (CORREC/ARI-ID/BE0) (error correction status, SK detection, error block count) 18 SYNC Block synchronization detection output 19 RDS-ID RDS detection output 20 DO Data output 21 CL Clock input 22 DI Data input 17 I/O* Output Vssd Vssd Serial data interface (CCB) S Input 23 CE Chip enable 24 SYR Synchronization and RAM address reset (active high) 14 Vddd Digital system power supply (+5V) − − 15 Vssd Digital system ground − − Vssd Note : * Normally function as an output pin. Used as an I/O pin in test mode, which is not available to user applications. No. 6123-6/18 LC72722PM CCB output data format 1. Each block of output data consists of 32 bits (4 bytes), of which 2 bytes are RDS data and 2 bytes are flag data. 2. Any number of 32-bits output data blocks can be output consecutively. 3. When there is no data that can be read out in the internal memory, the system outputs blocks of all-zero data consecutively. 4. If data readout is interrupted, the next read operation starts with the 32-bit data block whose readout was interrupted. However, if only the last bit is remaining to be read, it will not be possible to re-read that whole block. 5. The check bits (10 bits) are not output. 6. The data valid (OWD) must not be referred to. 7. When the first leading bits are not “1010”, the read in data is in invalid, and read operation is cancelled. CCB address 6C B B B B A A A A 0 1 2 3 0 1 2 3 DI 0 0 1 1 0 1 1 0 Last bit Output data / first bit 1 DO 0 1 O R A S D D D D D B B R R E E D D D D D D D D D D 0 W B F F R Y E 1 1 1 1 1 1 D 2 1 0 E 2 1 0 D 1 0 I C 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 (8) RDS data (7) Error information flags (6) Synchronization established flag (5) ARI(SK) detection flag (4) RAM data remaining flags (3) Consecutive RAM read out possible flag (2) Offset word information flags (1) Offset word detection flag Fixed pattern (1010) (1) Offset word detection flag (1bit) : OWD OWD Offset word detection 1 Detected 0 Not detected (protection function operating) (2) Offset word information flag (3bit) : B0 to B2 B 2 B 1 B 0 Offset word 0 0 0 A 0 0 1 B 0 1 0 C 0 1 1 C’ 1 0 0 D 1 0 1 E 1 1 0 Unused 1 1 1 Unused No. 6123-7/18 LC72722PM (3) Consecutive RAM read out possible flag (1bit) : RE RE RAM data information 1 The next data to be read out is in RAM 0 This data item is the last item in RAM, ant the next data is not present. (4) RAM data remaining flag (2bits) : RF0,RF1 RF1 RF0 Remaining data in RAM (number of blocks) 0 0 1 to 7 0 1 8 to 15 1 0 16 to 23 1 1 24 Caution : This value is only meaningful when RE is 1. When RE is 0, there is no data in RAM, even if RF is 00. If a synchronization reset was applied using SYR, then the backward protection block data that was written to memory is also counted in this value. (5) ARI(SK) detection flag (1bit) : ARI ARI SK signal 1 Detected 0 Not detected (6) Synchronization established flag (1bit) : SYC SYC Synchronization detection 1 Synchronized 0 Not synchronized Caution : This flag indicates the synchronization state of the circuit at the point when the data block being output was received. On the other hand, the SYNC pin (pin18) output indicates the current synchronization state of the circuit. (7) Error information flags (3bits) : E0 to E2 E 2 E 1 E 0 Number of bits corrected 0 0 0 0 (no errors) 0 0 1 1 0 1 0 2 0 1 1 3 1 0 0 4 1 0 1 5 1 1 0 Correction not possible 1 1 1 Unused Caution : If the number of errors exceeds the value of the EC0 to EC2 setting (see the section on the CCB input format), the error information flags will be set to the “Correction not possible” value. (8) RDS data (16bits) : D0 to D15 This data is output with the MSB first ant the LSB last. Caution : When error correction was not possible, the input data is output without change. No. 6123-8/18 LC72722PM CCB Input data format IN1 data, first bit [1] CCB address 6A DI B B B B A A A A 0 1 2 3 0 1 2 3 F F F F S B S S S S Y S 0 1 2 3 R O E E E W C C C E 0 1 2 E E C C C T 3 4 0 0 1 0 1 0 1 1 0 (12) Circuit control (5) Error correction method setting (4) RAM write control (3) Synchronization and RAM address reset (2) Synchronization detection method setting (1) Synchronization protection method setting IN2 data, first bit [2] CCB address 6B DI B B B B A A A A 0 1 2 3 0 1 2 3 C T 1 S S P P P P P X R P P T T T L L S M 0 1 0 1 2 0 1 T T T T S S S S 0 1 2 3 1 1 0 1 0 1 1 0 (11) Test mode settings (10) Output pin settings (9) RDS/RBDS selection (8) Demodulation circuit phase control (7) Crystal oscillator frequency selection (6) Intermittent DO output setting (12) Circuit control Caution : The bits labeled with an asterisk must be set to 0. (1) Synchronization protection (forward protection) method setting (4bits) : FS0 to FS3 FS3 = 0 : If offset words in the correct order could not be detected continuously during the number of blocks specified by FS0 to FS2, take that to be a lost synchronization sate. FS3 = 1 : If blocks with uncorrectable errors were received consecutively during the number of blocks specified by FS0 to FS2, take that to be a lost synchronization state. F S 0 F S 1 F S 2 Condition for detecting lost synchronization 0 0 0 If 3 consecutive blocks matching the FS3 condition are received. 1 0 0 If 4 consecutive blocks matching the FS3 condition are received. 0 1 0 If 5 consecutive blocks matching the FS3 condition are received. 1 1 0 If 6 consecutive blocks matching the FS3 condition are received. 0 0 1 If 8 consecutive blocks matching the FS3 condition are received. 1 0 1 If 10 consecutive blocks matching the FS3 condition are received. 0 1 1 If 12 consecutive blocks matching the FS3 condition are received. 1 1 1 If 16 consecutive blocks matching the FS3 condition are received. Initial value : FS0 = 0, FS1 = 1, FS2 = 0, FS3 = 0 (2) Synchronization detection method setting (1bit) : BS BS Synchronization detection conditions 0 If during 3 blocks, 2 blocks of offset words were detected in the correct order. 1 If the offset words were detected in the correct order in 2 consecutive blocks. Initial value : BS = 0 No. 6123-9/18 LC72722PM (3) Synchronization and RAM address reset (1bit) : SYR SYR 0 Synchronization detection circuit Normal operation (reset cleared) 1 Forced to the unsynchronized state (synchronization reset) RAM Normal write (See the description of the OWE bit) After the reset is cleared, start writing from the data prior to the establishment of synchronization, i.e. the data in backward protection. Initial value : SYR = 0 Caution : 1. To apply a synchronization reset, set SYR to 1 temporarily using CCB, and then set it back to 0 again using CCB. The circuit will start synchronization capture operation at the point SYR is set to 0. 2. The SYR pin (pin24) also provides an identical reset control operation. Applications can use either method. However, the control method that is not used must be set to 0 at all times. Any pulse with a width of over 250 ns will suffice. 3. A reset must be applied immediately after the reception channel is changed. If a reset is not applied, reception data from the previous channel may remain in on-chip memory. 4. Data read out after a synchronization reset is read out starting with the backward protection block data preceding the establishment of synchronization. (4) RAM write control (1bit) : OWE OWE RAM write conditions 0 Only data for which synchronization had been established is written. Data for which synchronization not has been established (unsynchronized data) is also written. (However, this applies when SYR = 0.) 1 Initial value : OWE = 0 (5) Error correction method setting (5bits) : EC0 to EC4 E C 0 0 E C 1 0 E C 2 0 1 0 1 0 1 0 1 0 1 1 0 0 1 1 0 0 0 1 1 1 1 Number of bits corrected 0 (error detection only) 1 or fewer bits 2 or fewer bits 3 or fewer bits 4 or fewer bits 5 or fewer bits Illegal value Illegal value E C 3 0 E C 4 0 MODE0 Hard decision 1 0 MODE1 Soft decision A 0 1 1 1 MODE2 Soft decision B Illegal value Soft-decision setting Initial values : EC0 = 0, EC1 = 1, EC2 = 0, EC3 = 0, EC4 = 1 Caution : 1. If soft-decision A or soft-decision B is specified, soft-decision control will be performed even if the number of bits corrected is set to 0 (error detection only). With these settings, data will be output for blocks with no errors. 2. As opposed to soft-decision B, the soft-decision A setting suppresses soft decision error correction. (6) Intermittent DO output setting SP0 SP1 DO output state 0 0 DO goes low when one or more blocks of data are written to memory. 1 0 DO goes low when 4 or more blocks of data are written to memory. 0 1 DO goes low when 8 or more blocks of data are written to memory. 1 1 DO goes low when 12 or more blocks of data are written to memory. Initial values : SP0 = 0, SP1 = 0 No. 6123-10/18 LC72722PM (7) Crystal oscillator frequency selection (1bit) : XS XS = 0 : 4.332MHz (Initial value : XS = 0) XS = 1 : 8.664MHz (8) Demodulation circuit phase control (2bits) : PL0, PL1 PL0 PL1 Demodulation circuit phase control 0 0/1 < Normal operation > when ARI presence or absence is unclear. 1 0 1 If the circuit determines that the ARI signal is absent : 90° phase If the circuit determines that the ARI signal is present : 0° phase Initial values : PL0 = 0, PL1 = 1 Caution : 1. When PL0 is 0 (normal operation), the IC detects the presence or absence of the ARI signal and reproduces the RDS data by automatically controlling the demodulation phase with respect to the reproduced carrier. However, the initial phase following a synchronization reset is set by PL1. 2. If PL0 is set to 1, the demodulation circuit phase is locked according to the PL1 setting at either 90° (PL1 = 0) or 0° (PL1 = 1), allowing RDS data to be reproduced. When ARI is not present, PL1 should be set to 0, since the RDS data is reproduced by detecting at a phase of 90° with respect to the reproduced carrier. When ARI is present, PL1 should be set to 1, since detection is at 0°. In cases where the ARI presence is known in advance, more stable reproduction can be achieved by fixing the demodulation phase in this manner. (9) RDS/RBDS(MMBS) selection (1bit) : RM RM RBDS 0 None 1 Provided Decoding method Only RDS data is decoded correctly (Offset word E is not detected.) RDS and MMBS data is decoded correctly (Offset word E is also detected.) Initial value : RM=0 (10) Output pin settings (3bits) : PT0 to PT2 These bits control the T3, T4, T5, T6, T7, SYNC, and RDS-ID pins MODE P T 0 P T 1 P T 2 0 1 2 3 4 5 6 7 0 1 0 1 0 1 0 1 0 0 1 1 0 0 1 1 0 0 0 0 1 1 1 1 T3 T4 T5 T6 RDCL RDDA RSFT ERROR 57K − − − − − − − − − − − − − − − − − − − − − − T7 TP BE1 CORREC ARI-ID TA BE0 − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − : open, , : Output enabled ( = reverse polarity) Initial value : PT0 = 1, PT1 = 1, PT2 = 0 (Mode 3) Caution : 1. When PT2 is set to 1, the polarity of the T6(ERROR/57K/TP), T7(CORREC/ARI-ID/TA), SYNC, and RDS-ID pins changes to active high. 2. The output pins (T3 to T7, SYNC, and RDS-ID) are all open-drain pins, and require external pull-up resistors to output data. Mode1 (PT2 = 0) TP = 0 detected TP = 1 detected TP = Traffic program code Pin T6 (TP) High (1) Low (0) No. 6123-11/18 LC72722PM Mode1 (PT2 = 0) Pin T7 (TA) TA = 0 detected High (1) TA = 1 detected TA = Traffic announcement code Low (0) Mode2 (PT2 = 0) No SK SK present Pin T7 (ARI-ID) High (1) Low (0) Mode3 (PT2 = 0) Correction not possible Errors corrected No errors Pin T6 (ERROR) Low (0) High (1) High (1) Pin T7 (CORREC) Low (0) Low (0) High (1) Pin T6 (BE1) Pin T7 (BE0) B=0 Low (0) Low (0) 1 ≤ B ≤ 20 Low (0) High (1) 20 < B ≤ 40 High (1) Low (0) Mode = 4 Number of error blocks (B) 40 < B ≤ 48 High (1) High (1) These pins indicate the number of blocks in a set of 48 blocks that had errors before correction. The output polarity of these pins is fixed at the values listed in the table. Mode (PT2 = 0) The SYNC pin When synchronized : Low (0), When unsynchronized: High (1) When synchronized : Goes high for a fixed period (421 μs) at the start of a block and then goes low. When unsynchronized : High (1) 0 to 2 3 Caution : The output indicates the synchronization state for the previous block. When PT2 = 0 The RDS-ID pin No RDS High (1) RDS present Low (0) (11) Test mode settings (4bits) : TS0 to TS3 Initial values : TS0 = 0, TS1 = 0, TS2 = 0, TS3 = 0 (Applications must set these bits to the above values.) Notes : The T1 and T2 pins (pins 7 and 8) are related to test mode as follows. Pin T1 Pin T2 IC operation 0 0 Normal operating mode 0 1 Standby mode (crystal oscillator stopped) 1 0/1 The T1 pin must be tied to VSS (0V). IC test mode Notes These states are user settable Users cannot use this state (12) Circuit control (2 bits) : CT0 and CT1 Item CT0 RSFT control CT1 RDS-ID detection condition Control When set to 1, soft-decision control data (RSFT) is easier to generate. When set to 1, the RDS-ID detection conditions are made more restrictive. Initial value : CT0 = 0, CT1 = 0 No. 6123-12/18 LC72722PM RDCL / RDDA / RSFT and ERROR / CORREC / SYNC output timing (1) Timing 1 421 μs 421 μs Tp1 RDCL output RDDA output RSFT output 17 μs Tp2 17 μs Note : When PT2 = 0, RDDA and RSFT must be acquired on the falling edge of RDCL. Error crrection Sync NG Sync OK Sync OK Sync OK Sync OK Sync OK Sync NG Data corrected No errors No errors Data corrected Uncorrectable Input data Uncorrectable (2) Timing 2 (mode 3, PT2 = 0) Tp1 Tp1 Sync NG SYNC output ERROR output CORREC output No. 6123-13/18 LC72722PM Serial Data Input and Output Methods Data is input and output using the CCB (Computer Control Bus), which is Our audio IC serial bus format. This IC adopts an 8-bit address CCB format. I/O mode (LSB) B0 B1 Address B2 B3 (MSB) A0 A1 A2 A3 [1] IN1 (6A) 0 1 0 1 0 1 1 0 [2] IN2 (6B) 1 1 0 1 0 1 1 0 [3] OUT (6C) 0 0 1 1 0 1 1 0 Comment Control data input mode, also referred to as “ serial data input ” mode. 16bit data input mode Data output mode The data for multiple blocks can be output sequentially in this mode. I/O mode determined CE 1 CL 2 B0 DI B1 B2 B3 A0 A1 A2 A3 First Data IN1/2 1 First Data OUT DO 2 First Data OUT 1 For the CL normal high state 2 For the CL normal low state No. 6123-14/18 LC72722PM (1) Serial data input (IN1 / IN2) tSU, tHD, tEL, tES, tEH ≥ 0.75μs tLC < 1.15μs tCE < 20 ms CL : Normal high tEL tCE tES tEH CE CL tSU tHD B0 DI B1 B2 B3 A0 A1 A2 FS0 CT1 A3 FS1 0 FS2 SP0 FS3 SP1 EC3 TS0 EC4 TS1 CT0 TS2 0 TS3 tLC Internal data CL : Normal low tEL tCE tES tEH CE CL tSU tHD B0 DI B1 B2 B3 A0 A1 FS0 CT1 A3 A2 FS1 0 FS2 SP0 FS3 SP1 EC3 TS0 EC4 TS1 CT0 TS2 0 TS3 tLC Internal data (2) Serial data output (OUT) tSU, tHD, tEL, tES, tEH ≥ 0.75μs tDC, tDH < 0.46μs tCE < 20 ms CL : Normal high tEL tCE tES tEH CE CL tSU tHD B0 DI B1 B2 B3 A0 A1 A2 A3 tDC tDC 1 DO CL : Normal low tEL 0 tDH 1 0 D3 D2 D1 tCE tES D0 tEH CE CL tSU DI B0 tHD B1 B2 B3 A0 A1 A2 A3 tDC 1 DO tDH tDC 0 1 0 D3 D2 D1 D0 Cautions : 1. Since the DO pin is an n-channel open-drain output, the transition times (tDC, tDH) will differ with the value of the pull-up resistor used. 2. The CE, CL, DI, and DO pins can be connected to the corresponding pins on other ICs that use the CCB interface. (However, we recommend connecting the DO and CE pins separately if the number of available microcontroller ports allows it.) 3. Serial data I/O becomes possible after the crystal oscillator starts oscillation. No. 6123-15/18 LC72722PM (3) Serial data timing CL : Normal high tCE VIH CE tCL tCH VIH VIL CL VIL tES tEL VIH VIL DI VIH VIL VIH tEH VIH VIL tSU tHD tDC tDH DO tLC Internal data latch New Old CL : Normal low tCE VIH CE tCH tCL VIH VIL CL VIH VIL tEL VIH VIL DI tSU VIL VIL VIL tEH tES VIH VIL tHD tDC tDH tDC DO tLC Old Internal data latch Parameter Symbol Conditions min typ max New Unit Data setup time tSU DI, CL 0.75 μs Data hold time tHD DI, CL 0.75 μs Clock low level time tCL CL 0.75 μs Clock high level time tCH CL 0.75 μs CE wait time tEL CE, CL 0.75 μs CE setup time tES CE, CL 0.75 μs CE hold time tEH CE, CL 0.75 μs CE high level time tCE CE Data latch transition time tLC Data output time tDC DO, CL tDH DO, CE Differs with the value of the pull-up resistor used. 20 ms 1.15 μs 0.46 μs 0.46 μs No. 6123-16/18 LC72722PM DO pin operation This IC incorporates a RAM data buffer that can hold up to 24 blocks of data. At the point when one block of data is written to this RAM, the IC issues a read request by switching the DO pin from high to low. The DO pin always goes high for a fixed period (Tdo = 265 μs) after a readout and CE goes low. When all the data in the data buffer has been read out, the DO pin is held in the high state until a new block of data has been written to the RAM. If there is data that has not yet been read remaining in the data buffer, the DO pin goes low after the Tdo time has elapsed. After a synchronization reset, the DO pin is held high until synchronization is established. It goes low at the point the IC synchronizes. When the DO pin is high following the 265 μs period (Tdo) after data is read out. Here, the buffer is in the empty state, i.e. the state where new data has not been written. After this, when the DO pin goes low, applications are guaranteed to be able to read out that data without it being overwritten by new data if they start a readout operation within 480 ms of DO going low. Tdo CE pin T DO pin (Last data)-1 New data Last data DO check (Tdo < T) When DO goes low 265 μs after data is read out Here, there is data that has not been read out remaining in the data buffer. In this case, applications are guaranteed to be able to read out that data without it being overwritten by new data if they start a readout operation within 20 ms of DO going low. (Note that this is the worst case condition.) Tdo CE pin T DO pin (Last data)-2 Last data (Last data)-1 DO check (Tdo < T) Notes : 1. Although an application can determine whether or not there is data remaining in the buffer by checking the DO level with the above timing, checking the RE and RF flags in the serial data is a preferable method. 2. Applications are not limited to reading out one block of data at a time, but rather can read out multiple blocks of data continuously as described above. When using this method, if an application references the RE and RF flags in the data while reading out data, it can determine the amount of data remaining. However, the length of the period for data readout (the period the CE pin remains high) must be kept under 20 ms. 3. If the DO pin is shared with other ICs that use the CCB interface, the application must identify which IC issued the readout request. One method is to read out data from the LC72722PM and either check whether meaningful data has been read (if the LC72722PM is not requesting a read, data consisting of all zeros will be read out) or check whether the DO level goes low within the 256 μs following the completion of the read (if the DO pin goes low, then the request was from another IC). No. 6123-17/18 LC72722PM Sample Application circuit 10 μF Vssa + MPXIN 330 pF Vdda 0.1 μF 1 2 3 4 Vssa 5 560 pF 6 7 8 Vssd NC NC NC 9 10 11 12 22 pF VREF SYR MPXIN CE Vdda DI Vssa CL FLOUT DO CIN RDS-ID T1 SYNC T2 T7 T3 T6 T4 Vssd T5 Vddd XOUT XIN 4.332 MHz Vssd 24 SYR 23 Vssd CE 22 DI 21 20 19 18 17 16 Vddd 10 kΩ Vddd 10 kΩ Vddd 10 kΩ DO RDS-ID SYNC NC NC 15 14 CL Vssd 0.1 μF Vddd 13 22 pF Vssd Caution : 1. Determine the value of the DO pin pull-up resistor based on the required serial data transfer speed. 2. If the SYR pin is unused, it must be connected to ground. ON Semiconductor and the ON logo are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of SCILLC’s product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent-Marking.pdf. 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This literature is subject to all applicable copyright laws and is not for resale in any manner. PS No. 6123-18/18