CXA2534Q

CXA2534Q 4-Channel CD Motor Driver Description CXA2534Q is a 4-channel H-bridge motor driver IC designed for portable CD systems. It has a built-in DC to DC converter controller that allows voltage step-up to typically 3.2 V; this voltage can be used to power the system DSP, SSP and micro-controller. In addition, it also provides a PWM regulated power supply to the H-bridge output stage so as to ensure high efficiency. Features • 4 channels of H-bridge drivers • PWM regulated power supply for H-bridge output stages • Step-up DC to DC converter controller for system power supply • Start and off controls with soft start capability • Reset pulse • Short circuit protect • Over-voltage protect • Low battery voltage detection • Rechargeable battery charger • General purpose operational amplifier • Thermal shut-down for battery charger and Hbridge driver (170 °C/140 °C) • Direct interface with wired remote controller possible Applications Portable CD player Structure Bipolar silicon monolithic IC 48 pin QFP (Plastic) Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits. —1— E99145-TE CXA2534Q Absolute Maximum Ratings (Ta=25 °C) Item Supply voltage Spindle channel output current Sled channel output current Focus channel output current Track channel output current Allowable power dissipation operating temperature Storage temperature Symbol VCC1, VCC2, PVCC Io (spindle) Io (sled) Io (focus) Io (track) PD Topr Tstg Rating 13.5 400 300 200 200 660 –20 to +75 –65 to +150 Unit V mA mA mA mA mW °C °C Recommended Operating Conditions (Ta=25 °C) Item System 1 supply voltage System 2 supply voltage Power VCC Battery supply voltage Battery charger supply voltage Operating temperature Symbol VCC1 VCC2 PVCC Batt ChgVCC Ta Min 2.7 2.7 — 1.5 3 –10 Typ 3.2 3.2 PWM 2.4 4.5 25 Max 5.5 5.5 Batt 8 8 70 Unit V V V V V °C —2— CXA2534Q Block Diagram 24 25 RESET OFF PWMFIL PGND PSW START KEY IN REMO BATT DC IN GND ISET CHGVCC 23 22 21 20 19 18 17 16 15 14 MUTE 13 12 11 10 BRAKE MUTE SP IN PGND SL BRAKE SLED IN FT MUTE FOCUS IN TRACK IN VCC2 VREF VCC1 OP+ OP O PGND 26 27 BTL BTL TSD BTL BTL 28 SP MUTE 48 OP– FOCUS+ FOCUS– TRACK+ TRACK– SLED+ SLED– PVCC PVCC EMP SP+ SP– 29 PREDRIVER PEAK DETECT PWM DRIVER PREDRIVER PREDRIVER EMPTY DETECT WIRED REMOTE CHARGER POWER ON/OFF PRETRIANGLE DRIVER WAVE GEN OVER VOLTAGE PROTECT ERROR GND 30 31 32 33 RESET 34 35 TSD 36 SW DRIVER 37 SEL 38 BSEN 39 BATT 40 SW 41 DEAD 42 EO 43 EI 44 SPRT 45 TR 46 TC 47 CLK —3— 1 SHORT PROTECT 2 3 4 5 6 7 8 9 CXA2534Q Pin Description Pin No. Symbol Pin Voltage Equivalent circuit VCC1 VCC1 Description 1 OP O — 1 Output pin of built-in operational amplifier VCC1 VCC1 2 OP+ 2 48 Non-inverting input pin of operational amplifier — 48 OP– Inverting input pin of operational amplifier 3 VCC1 3.2 V VCC2 ×4 Power supply input to DC-DC controller circuits 4 4 VREF 1.6 V 30k Reference Voltage 75k 5 VCC2 3.2 V Power supply input to pre-driver circuits —4— CXA2534Q Pin No. 6 Symbol Pin Voltage Equivalent circuit VCC2 Description TRACK IN Tracking error signal input pin 7 FOCUS IN 1.6 V 6 7 9 11k Focus error signal input pin 9 SLED IN Sled error signal input pin VCC2 8 FT MUTE Focus and Tracking mute input pin 0V 8 75k 10 75k 10 SL BRAKE Sled motor brake input pin 11 PGND 28 0V Power ground for H-bridge drivers VCC2 12 SP IN 1.6 V 12 7.5k Spindle error signal input pin VCC2 75k 13 SP MUTE 0V 75k 13 75k 75k Spindle mute input —5— CXA2534Q Pin No. 14 Symbol Pin Voltage Equivalent circuit Description PVCC 19 15 16 17 18 20 21 22 23 TRACK– TRACK+ FOCUS– FOCUS+ — Power supply input for H-bridge drivers Negative output pin to tracking motor 14 19 Positive output pin to tracking motor Negative output pin to focus motor 16 15 17 19 21 Positive output pin to focus motor Negative output pin to sled motor Positive output pin to sled motor — SLED– SLED+ SP– SP+ 18 20 22 11 28 Negative output pin to spindle motor Positive output pin to spindle motor 24 24 EMP — Battery empty detection output pin VCC1 VCC1 90k 25 RESET VCC1 25 Reset output pin —6— CXA2534Q Pin No. Symbol Pin Voltage Equivalent circuit Description VCC1 VCC1 180k 26 OFF VCC1 30k 26 Input pin to put IC into standby mode VCC2 VCC2 2k 27 PWMFIL — 27 PWM filter pin 2k BATT BATT 29 29 PSW — PWM switching output pin 15 —7— CXA2534Q Pin No. Symbol Pin Voltage Equivalent circuit BATT 390k BATT Description 30 START Batt 200k 30 Input pin to start the IC 32 31 KEY IN — 200k 50k 31 Input pin from wired remote to start the IC 32 REMO BATT — BATT 30k Power supply to the built-in wired remote interface circuit 33 33 DC IN 0V 100k Input pin to start the IC when AC adapter is inserted 34 GND 0V CHGVCC Ground 35 ISET 1.2 V 950 35 Set charging current of built-in battery charger 36 CHGVCC 4.5 V Power supply input to the battery charger —8— CXA2534Q Pin No. Symbol Pin Voltage Equivalent circuit BATT 220k Description 68k 37 SEL — 37 30k Detection input pin for battery or AC adapter operation and Battery charging current output pin BATT 38 16.5k 71k 38 BSEN Batt 10k 19k Detection input pin for battery empty detection 11.5k 39 BATT 2.4 V BATT BATT BATT Battery input pin 40 SW — 250 40 DC to DC controller output pulses 9k —9— CXA2534Q Pin No. Symbol Pin Voltage VCC1 Equivalent circuit Description 18k 41 DEAD 0.88 V 41 65k 50k Soft start pin VCC1 VCC1 42 EO — 42 Output pin of error amplifier VCC1 VCC1 35k 43 EI 1.2 V 43 Input pin of error amplifier 21k VCC1 VCC1 44 SPRT 0V 44 Short protection pin 220k —10— CXA2534Q Pin No. Symbol Pin Voltage Equivalent circuit VCC1 Description 5k 45 TR 1.2 V 45 Together with the capacitor at TC, set the start-up and free running frequency of sawtooth VCC1 BATT ×3 46 TC — 46 ×2 Together with the resistor at TR, set the start-up and free running frequency of sawtooth 420k VCC1 10k 47 CLK — 47 Synchronizing clock pulse input —11— CXA2534Q Electrical Specifications If not specified, Ta=25 °C, Batt=2.4 V, VCC1=VCC2=3.2 V, Vref=1.6 V, ChgVCC=0 V, fCLK=88.2 kHz Item 1. Overall Batt standby current Batt quiescent current VCC1 quiescent current VCC2 quiescent current ChgVCC quiescent current 2. H-Bridge driver Spindle Voltage gain Sled Focus Track Gain difference Spindle Input impedance Sled Focus Track Spindle Maximum output voltage Sled Focus Track Upper Tr saturation voltage Lower Tr saturation voltage Spindle Sled Focus Track Spindle Sled Focus Track Spindle Output offset voltage Sled Focus Track Spindle Dead band Sled Focus Track Spindle mute on Spindle mute off Sled brake on Sled brake off Gv (sp) Gv (sled) Gv (focus) Gv (track) ∆Gv Rin (sp) Rin (sled) Rin (focus) Rin (track) Vom (sp) Vom (sl) Vom (foc) Vom (tra) VSAT (sp) VSAT (sl) VSAT (foc) VSAT (tra) VSATL (sp) VSATL (sl) VSATL (foc) VSATL (tra) VOI VOO (sp) VOO (sled) VOO (focus) VOO (track) VDB (sp) VDB (sled) VDB (focus) VDB (track) VMSP(on) VMSP(off) VBSL(on) VBSL(off) –5 –10 –10 –10 2 — 2 — 20 15 15 15 — — — — 45 40 40 40 — 0.8 — 0.8 mV mV mV mV V V V V SP IN=1.8V SP IN=1.8V SLED IN=1.8V SLED IN=1.8V –50 0 50 mV Vref=IN=1.6 V 21.9 14 14 14 –2 5.7 8.8 8.8 8.8 1.9 1.9 1.9 1.9 — — — — — — — — –5 23.9 15.5 15.5 15.5 0 7.5 11 11 11 2.1 2.05 2.05 2.05 280 280 230 230 230 250 200 200 0 25.9 17 17 17 2 11 15 15 15 — — — — 400 400 400 400 400 400 400 400 5 dB dB dB dB dB kΩ kΩ kΩ kΩ V V V V mV mV mV mV mV mV mV mV mV Io=400 mA, SP IN=0 and 3.2 V Io=300 mA, SLED IN=0 and 3.2 V Io=200 mA, FOCUS IN=0 and 3.2 V Io=200 mA, TRACK IN=0 and 3.2 V Io=400 mA, SP IN=0 and 3.2 V Io=300 mA, SLED IN=0 and 3.2 V Io=200 mA, FOCUS IN=0 and 3.2 V Io=200 mA, TRACK IN=0 and 3.2 V IN=0 and 3.2 V, PVCC=4 V IN∗=1.7 and 1.8 V IST IBAT IVCC1 IVCC2 IChgVCC — — — 0 2 4.9 4.2 0.79 2 3.2 6.7 6.4 1.2 µA mA mA mA mA Batt=9 V, VCC1=VCC2=0 V PVCC=PWM, FT Mute=3.2 V PVCC=0.45 V, FT Mute=3.2 V, EI=0 V PVCC=0.45 V, FT Mute=3.2 V ChgVCC=4.5 V, Rch=open Symbol Min. Typ. Max. Unit Condition Input offset voltage ∗ IN means SP IN, SLED IN, FOCUS IN or TRACK IN. —12— CXA2534Q Item Focus/Track mute on Focus/Track mute off Vref on voltage Vref off voltage 3. PWM driver for PVCC PSW output current PVCC shift voltage PVCC leakage current PWM transconductance 4. DC to DC converter 4.1 Error amplifier VCC1 threshold voltage Hi error output voltage Lo error output voltage SPRT voltage (normal) SPRT output current (EO=H) SPRT output current (OFF=L) SPRT output current (Over-voltage) SPRT impedance SPRT threshold voltage Over voltage protect threshold 4.3 Sawtooth waveform SW high output voltage (Starting) SW high output voltage (Normal) SW low output voltage SW start freq SW free running freq SW synchronized freq Start freq duty cycle Free freq duty cycle Synchronized freq duty cycle 4.4 Soft start DEAD pin impedance DEAD pin voltage Symbol VMFT (on) VMFT (off) Vref (on) Vref (off) IPSW VSHIF IPVCC (leakage) GPWM Min. — 2 1.2 — 10 0.2 — 1/67.5 Typ. — — — — 13 0.3 0 1/50 Max. 0.8 — — 0.8 17 0.4 3 1/32.5 Unit V V V V mA V µA 1/kΩ Condition FOCUS IN=1.8 V FOCUS IN=1.8 V SP IN=1.8 V SP IN=1.8 V SLED IN=2.1 V SLED IN=1.8 V, PVCC–SLED+ PVCC=9 V, VCC1=VCC2=Batt=0 V SL IN=1.8 V, PVCC=1.2 to 1.4 V VCC1TH VEOH VEOL VSPR ISPR1 ISPR2 ISPR3 RSPR VSPR (Th) VBSEN (Th) 3.05 1.5 — — 6 12 12 154 1.1 8 3.2 1.65 — 0.05 10 20 20 220 1.23 8.4 3.37 — 0.2 0.1 16 32 32 297 1.36 9 V V V V µA µA µA kΩ V V EI=0.7 V, TC=0 V BSEN Voltage Batt=TC=1.5 V, VCC1=VCC2=0 V, Io=–2 mA, START=LO TC=0 V, Io=–10 mA, EI=0.7 V SPRT=0 V TC=2 V, Io=10 mA TC=420 pF, VCC1=VCC2=0 V, START=LO TC=420 pF, CLK=0 V TC=420 pF, CLK=88.2 kHz TC=420 pF, VCC1=VCC2=0 V TC=420 pF, EI=0.7 V, CLK=0 V TC=420 pF, EI=0.7 V EI=0.7 V, Io=–100 µA EI=1.36 V, Io=100 µA EI=1.36 V EI=0.7 V, VSPR=0 V EI=1.36 V, OFF=0 V, VSPR=0 V EI=1.36 V, Batt=9.5 V, VSPR=0 V 4.2 Short circuit and Over voltage protection VSWH (start) VSWH (nor) VSWL (nor) fSW1 fSW2 fSW3 DSW1 DSW2 DSW3 RDEAD VDEAD 0.78 1 — 55 60 — 45 70 65 55 0.72 0.98 1.5 0.1 85 70 88.2 55 80 75 80 0.82 1.13 — 0.4 115 82 — 65 90 85 105 0.92 V V V kHz kHz kHz % % % kΩ V —13— CXA2534Q Item 4.5 Input OFF threshold voltage OFF current START on threshold voltage START off threshold voltage START pin current Clock input voltage Clock current 4.6 Start Start cut threshold voltage Start cut hysteresis Discharge threshold voltage 5. EMPTY Empty detect threshold 1 Empty detect threshold 2 Empty detect hysteresis Empty detect hysteresis EMPTY pin voltage EMPTY pin leakage current BSEN pin impedance BSEN pin leakage current SEL pin threshold voltage SEL pin threshold current 6. RESET Reset threshold voltage Reset hysteresis RESET pin RESET pin impedance 7. OP AMP Input bias current Input offset voltage High output voltage Low output voltage Output current (Source) Output current (Sink) Open loop gain Slew rate High Low Symbol VOFF (th) IOFF VSTART1 VSTART2 ISTART VCLKH VCLKL ICLK Min. — 55 — Batt– 0.3 9 2 — — Typ. — 80 — — 14 — — 5 Max. VCC–2 105 Batt–1 — 19 — 0.8 10 Unit V µA V V µA V V µA CLK=3.2 V EI=1.36 V OFF=0 V Condition VCC1=VCC2=0 V, TC=2 V VCC1=VCC2=0 V, TC=2 V START=0 V VST (th) VST (hs) VDIS VEMPT1 VEMPT2 VEMPH1 VEMPH2 VEMP IEMPL RBSEN IBSENL VSEL (th) ISEL (th) VRST (th) VRST (hy) VRST RRST IBIAS VIO VOH VOL ISOU ISIN GVO SR 2.3 — 1.25 1.9 1.5 — — — — 16.5 — 1.3 –2 85 — — 66 — –5 2.9 — — 0.4 — 0.5 2.5 200 1.45 2.0 1.6 50 50 — — 22.8 — — — 90 50 — 88 — 0 — — –8.5 0.8 70 1 2.7 — 1.65 2.1 1.7 — — 0.5 1 29 1 — — 95 — 0.4 118 250 5 — 0.2 –3 — — 1.5 V mV V V V mV mV V µA kΩ µA V µA % mV V kΩ nA mV V V mA mA dB V/µS VCC1=VCC2=0 V→3.2 V, START=0 V START=0 V VSEL=0 V (SEL=LOW) ISEL=–2 µA (SEL=HI Z) VSEL=0 V (SEL=LOW) ISEL=–2 µA (SEL=HI Z) Io=1 mA, BSEN=1 V BSEN=2.4 V VSEL=0 V VCC1=VCC2=0 V, BSEN=4.5 V VSEL (th)=Batt–SEL, BSEN=2 V Io=1 mA, VCC1=VCC2=2.8 V OP+=1.6 V RL=open RL=open RL=50 Ω to GND RL=50 Ω to VCC1 Vin=–75 dB, f=1 kHz —14— CXA2534Q Item 8. BATTERY CHARGER RCHG pin voltage RCHG pin impedance SEL pin leakage current (RCHG=open) SEL pin leakage current (ChgVCC=0.6 V) SEL pin voltage Symbol VRCHG RRCHG ISEL1 ISEL2 VSEL Min. 0.7 0.68 — — — Typ. 0.8 0.96 — — 0.45 Max. 0.9 1.16 1 1 1 Unit V kΩ µA µA V Condition ChgVCC=4.5 V, ISET=1.8 kΩ ChgVCC=4.5 V, ISET=0.5 and 0.6 V ChgVCC=4.5 V, ISET=open ChgVCC=0.6 V, ISET=1.8 kΩ ChgVCC=4.5 V, Io=300 mA, ISET=0 Ω Batt=4 V, VCC1=VCC2=0 V, TC=2 V, DC=IN=from 0 to 3 V Batt=4 V, VCC1=VCC2=0 V, TC=2 V, IKEYIN=from 0 to 10 µA 9. WIRED REMOTE INTERFACE DC IN pin threshold voltage KEY IN pin threshold current VDCIN (th) IKEYIN (th) 1 — — — — 5 V µA —15— B V14 I4 8,1.5W R4 I5 V11 BA S8 13 A I3 8,1.5W R7 R9 8,1.5W I2 I1 S21 V12 R6 R3 51k 8,1.5W V13 S17_2 AB C B AA BB AA B B AA B B AA B S17_1 S16 S15 S14 S13 S12 S11 S10 S9 C1 B S18 25 RESET 26 OFF 27 PWMFIL 28 PGND 47µ SP+ 23 SP– 22 EMP 24 PVcc 19 PVcc 14 SLED+ 21 SLED– 20 SP IN 12 S7 B A TRACK+ 16 TRACK– 15 V15 SP MUTE Electrical Characteristics Test Circuit C10 S19 PGND 11 S20 SL BRAKE 10 SLED IN 9 FT MUTE 8 A FOCUS IN 7 TRACK IN 6 Vcc2 5 VREF 4 Vcc1 3 OP+ 2 R15 OP O 1 S38_1 S38_2 V23 S28 S29 A I9 V22 I8 R5 10k V24 V25 V26 BA B S30 S31 S32 S33 S34 B A A BA B A B A I10 I11 I12 B I13 R8 39k S35 A 470p C4 V27 V29 S36_1 S36_2 B A V28 B C R10 10k C3 A 46 TC 47 CLK 48 OP– 45 TR 0.1µ I6 V10 L1 33µH D1 C3 FOCUS+ 18 FOCUS– 17 V16 RB400D S25 B C2 10p 2200p A A B B V9 S6 B A S5 B A V8 2SA1585S S22 29 PSW 30 START 31 KEY IN 32 REMO BATT P1 S23 S24 R100 V7 V6 S4 B A S3 B A V5 V200 V4 V3 R11 1k 37 SEL 38 BSEN 39 BATT 40 SW 41 DEAD 42 EO 43 EI 44 SPRT —16— CXA2534 IC01 A S26 33 DC IN 34 GND R2 100k A V100 V17 B A 47 B V18 A B A I7 V19 B 1.8k A S27 35 ISET R1 B V21 36 CHGVCC V20 R14 B C D 1M R13 20k R12 100k S2 A B 50 S1 A B V1 SIG V2 S37 470µ A B CXA2534Q CXA2534Q Application Circuit Spindle Motor SLED Motor To System Micro Controller Focus Coil FOCUS+ Tracking Coil To System Micro Controller SP MUTE 13 12 11 SP IN PGND PGND FOCUS– TRACK+ SLED+ SLED– PVCC TRACK– 15 EMP SP+ 0.1µ PGND 24 25 RESET OFF PWMFIL 23 SP– 22 21 20 19 18 17 16 PGND 47µ 26 PVCC 14 MUTE BRAKE 27 33µH GND 28 GND PGND MUTE 29 47 PGND PLAY 30 1µ GND GND 7 START KEY IN PREDRIVER PREDRIVER 8 PSW PREDRIVER PEAK DETECT PWM DRIVER 9 10p 100k PGND 2200p BTL BTL TSD BTL BTL 10 SL BRAKE SLED IN FT MUTE FOCUS IN TRACK IN VCC2 VREF VCC1 OP+ OP O Servo Processor PLAY/PAUSE STOP F. F. F. R. GND 32 33 0.1µ RESET CHARGER 34 GND ERROR SW DRIVER GND 35 36 WIRED REMOTE BOARD 37 SEL 38 BSEN 39 BATT 40 SW 41 DEAD 42 EO 43 EI 44 SPRT 45 TR 46 TC 47 CLK 48 OP– 0.1µ 8.2k 0.022µ 0.1µ GND 39k GND 470p GND DC-DC CONVERTOR AC Adapter Input 47µ GND GND 100µ GND Application circuits shown are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits or for any infringement of third party patent and other right due to same. —17— 1 1.4k CHGVCC TSD SHORT PROTECT 2 ISET 3 GND 4 DC IN WIRED REMOTE OVER VOLTAGE PROTECT 5 REMO BATT EMPTY DETECT POWER ON/OFF PRETRIANGLE DRIVER WAVE GEN 31 6 CXA2534Q Description of Operation 1. H-Bridge Driver a) Gain Setting The input resistances of the Sled, Focus and Track channels are 11 kΩ (typical); the input resistance of the Spindle channel is 7.5 kΩ (typical). The gain can be adjusted by connecting a external resistor, R at the input pin of the channel. Channel Sled channel Focus channel Track channel Spindle channel Unit GV = 20 log 55 kΩ 11 kΩ + R 110 kΩ 7.5 kΩ + R dB R - External Resistor GV = 20 log dB b) Mute The Spindle channel operates normally when the SP MUTE (pin 13) is open or at LOW (below 0.8 V). The output will be muted when the SP MUTE pin is at HIGH (above 2 V). This is a high impedance mute as the spindle output voltage will be not pulled to LOW. The Focus and Track channels share the same mute pin (pin 8). The channels are muted when the FT MUTE pin (pin 8) is open or at LOW level (below 0.8 V). When the Focus and Track channels are muted, the quiescent current at the VCC2 pin is also reduced by almost half. This is because the bias are removed when the mute is on. c) Thermal Shutdown The H-bridge Driver has an internal thermal shutdown circuit. All the channels outputs will be muted when the chip temperature exceeds 170 °C (typical) and restored when the chip temperature falls to 140 °C (typical). d) VREF pin When the VREF pin (pin 4) is below 1 V (typical), the H-bridge driver will be at standby mode and the quiescent current is zero (typical). e) Dead Band Dead band = 2 × input Resistance (attached external resistor + internal resistor) × 0.5 µA The dead band is depended on input resistance. Thus, the dead band varies with the gain settings. The dead band is 7.5 mV for Spindle channel and 11 mV for Sled, Focus and Track channels. —18— CXA2534Q f) PWM Driver For PVCC To ensure the good power efficiency of the H-bridge driver, a Buck DC-to-DC converter may be used to regulate the PVCC. The controller selects the peak voltage among the channels and used it to control the duty cycle of the PWM. External components necessary are: PNP transistor, inductor coil, diode and capacitors. The configuration of a Buck DC-to-DC converter is shown as follow: BATT 10pF 2200pF 100k 47 33µ 47µF 0.1µF PWMFIL 27 CXA2534Q PSW 29 PVCC 14 PVCC 19 g) Bypass Capacitor To have prevent noise, a bypass capacitor (roughly 0.1 µF) is connected from PVCC pin to the GND pin as close as possible. —19— CXA2534Q 2. DC-to-DC Converter a) VCC1 Voltage Setting The VCC1 voltage can be adjusted by varying the two external resistors, R1 and R2. The formula for VCC1 Voltage setting is: R1R3 VCC1 = 1.23 R1+R3 + R2R4 R2+R4 R2R4 R2+R4 (V) where R1 - External Resistor R2 - External Resistor R3 - 35 kΩ R4 - 21 kΩ CXA2534Q VCC1 3 R3 R1 EI 43 R2 R4 1.23V b) Short Circuit Protection If the VCC1 falls below the designed voltage for a long time, it will be considered as a short circuit at the VCC1. In this case, the IC will detect this prolong drop in VCC1 and turn off the IC. When the VCC1 is below the designed voltage, the error amplifier will output an HIGH at its EO pin (pin 42). The High level at EO pin will cause the SPRT pin’s capacitor (pin 44) to charge up by a constant current of 10 µA. Once the voltage is above 1.23 V (typical), the IC will turn off. The duration of the short circuit can be varied by the SPRT pin’s capacitor. 1.23V × CSPRT 10µA t= (sec) —20— CXA2534Q c) Soft Start During start-up of the IC, the duty cycle of the DC-to-DC converter is increased slowly to a maximum of 80 %. The VCC1 voltage will also increase slowly. This is known as soft start. During the soft start, the duty cycle of the SW pin (pin 40) is dependent on the voltage at the DEAD pin (pin 41). The DEAD pin is connected to a capacitor which is being charged up by an internal resistance of 65 kΩ. Therefore, the time taken for the duty cycle to reach the maximum is t = CSPRT × R (sec) where R = 65 kΩ d) Power Off To turn off the DC-to-DC Converter, a LOW level is applied to the OFF pin (pin 26). When the OFF pin is low, the IC will not turn off the DC-to-DC converter immediately but will charge up the SPRT pin’s capacitor with a constant current of 20 µA. Once the SPRT pin’s voltage is above 1.23 V, the IC will then shut down. Therefore, the delay is given by the formula below: 1.23 V × CSPRT 20 µA t= (sec) e) Over-Voltage Protection The IC will detect a over-voltage if the voltage at the BSEN pin is above 8.4 V (typical). When overvoltage occurred, the IC will shut down after a time delay. The time delay is determined by the time taken for the SPRT pin’s capacitor to charge above 1.23 V. The charging current for the SPRT pin capacitor is constant and is 20 µA. 1.23 V × CSPRT 20 µA t= (sec) f) Reset Pulse When the VCC1 voltage rises above 90 % of the designed value, the RESET pin (pin 25) will change from LOW level to HIGH level. A hysteresis of 50 mV (typical) is implemented to prevent the ‘chattering’ of the output at RESET pin. g) Empty Detection The EMP pin (pin 24) is used to indicate low battery voltage. When the BSEN pin falls below a certain threshold voltage, the EMP pin will change from HIGH to LOW level. There are two threshold voltages, depending on the SEL pin (pin 37). In order to prevent ‘chattering’ of the output at the EMP pin, a hysteresis of 50 mV (typical) is implemented. Threshold Voltage (typical) 2.0 V 1.6 V Recovery Voltage (typical) 2.05 V 1.65 V SEL pin LOW High - Z —21— CXA2534Q 3. Battery Charger The Battery Charger is separated from the rest of the circuit. The ChgVCC pin (pin 36) is the power supply pin to the charger circuit. The charging current is drawn in from the SEL pin (pin 37) and can be set by an external resistor at ISET pin (pin 35). The charger has a built-in thermal shut down circuit. The shut down temperature is set to 170 °C and 140 °C is the recovery temperature. 4. Wired Remote Interface When the IC is at standby, it can be activated by pulling the START pin (pin 30) or the KEY IN pin (pin 31) LOW. The START pin is controlled by the PLAY button on the main set and the KEY IN pin is controlled by the PLAY button on the wired remote control panel. The wired remote interface circuit is powered at REMO BATT pin (pin 32) which is connected to the BATT. To ensure that the voltage at REMO BATT pin is not greater than VCC1, a resistor and zener diode (Vz=3.1 V) may be necessary. The DC IN pin (pin 33) will detect a pulse through a series capacitor when a AC adapter is power on. This pulse will activate the IC also. —22— CXA2534Q Package Outline Unit : mm 48PIN QFP (PLASTIC) 15.3 ± 0.4 + 0.4 12.0 – 0.1 + 0.1 0.15 – 0.05 0.15 36 25 37 24 48 13 + 0.2 0.1 – 0.1 1 + 0.15 0.3 – 0.1 12 0.8 0.24 M + 0.35 2.2 – 0.15 PACKAGE STRUCTURE PACKAGE MATERIAL SONY CODE EIAJ CODE JEDEC CODE QFP-48P-L04 QFP048-P-1212 LEAD TREATMENT LEAD MATERIAL PACKAGE MASS EPOXY RESIN SOLDER / PALLADIUM PLATING 42/COPPER ALLOY 0.7g NOTE : PALLADIUM PLATING This product uses S-Pd PPF (Sony Spec.-Palladium Pre-Plated Lead Frame). —23— 0.9 ± 0.2 13.5