RX3140 Low Power IF Receiver IC the wireless IC company HiMARK Technology, Inc. reserves the right to change the product described in this datasheet. All information contained in this datasheet is subject to change without prior notice. HiMARK Technology, Inc. assumes no responsibility for the use of any circuits shown in this datasheet. Description The RX3140 is a low power IF receiver IC which is fully compatible with the Toshiba TA31142 IC and is suitable for use as the second IF downconverter in double-conversion paging systems. The RX3140 is well-suited for POCSAG paging applications and incorporates a 2-level FSK demodulator consisting of a quadrature FM demodulator, on-chip bit-rate filter, and 1-bit comparator. An on-chip 1 V regulator is provided for convenient biasing of off-chip circuitry. Features u u u u u u u u u u Extremely low power operation with power-down feature Built-in crystal oscillator for mixer local oscillator Mixer input frequency: 10 — 50 MHz Quadrature detector On-chip bit-rate filter Audio output 1-bit comparator with open collector output 1 V regulator 1.1 V low battery alarm SSOP-20 package (0.65 mm pitch) Block Diagram 20 19 MIX IN VSS 18 REG OUT 17 REG CON 16 ALM 15 FSK OUT 14 LOW 1-BIT BATTERY COMPARATOR ALARM 1.0 V REGULATOR CHA RGE 13 12 BS LPF OUT 11 LPF IN CHARGE/ DISCHARGE CIRCUIT MIXER QUAD DETECTOR OSCILLATOR IFAMP OSC OUT OSC IN 1 Revision B 2 MIX OUT 3 VCC 4 IFIN 5 FSK REF DEC 6 Page 1 7 IF OUT 8 AF OUT QUAD 9 10 May 2000 RX3140 the wireless IC company Pin Descriptions Number Name Description 1 OSCIN 2 OSCOUT Oscillator output (emitter) 3 MIXOUT Mixer output (2 KΩ output impedance) 4 VCC Number Name Description 14 CHARGE Two-state logic input to control charge-discharge circuit. (CHARGE = high = fast charge; CHARGE = low = slow charge) 15 FSKOUT Open collector NRZ comparator output (requires pull-up resistor) Oscillator input (base) Nominal 1.4 V supply 5 IFIN IF amplifier input (2 KΩ input impedance) 6 DEC IF amplifier de-coupling capacitor connection 16 ALM Open collector low battery alarm output (requires pullup resistor) 7 FSKREF 1-bit comparator reference input (requires external capacitor) 17 REGCON 1.0 V regulator control output for connection to external PNP base 1.0 V regulator input for connection to external PNP collector 8 IFOUT IF amplifier output 9 QUAD Quadrature FM demodulator input 18 REGOUT 10 AFOUT Quadrature FM demodulator output 19 VSS 20 MIXIN 11 LPFIN LPF operational amplifier input 12 LPFOUT LPF operational amplifier output 13 Revision B BS Ground Mixer input (5 KΩ input impedance) Two-state logic input to control receiver power up/ down. (BS = high = normal operation; BS = low = stand-by mode) Page 2 May 2000 RX3140 the wireless IC company Absolute Maximum Ratings VSS = 0 V Parameter Symbol Rating Unit Supply voltage VCC VSS – 0.3 to VSS + 3.5 V Operating temperature range TOPR –30 to 85 °C Storage temperature range TSTG –55 to 150 °C Soldering temperature range TSLD 255 °C Soldering time range tSLD 10 s Recommended Operating Conditions VSS = 0 V Value Parameter Supply voltage range Revision B Symbol VCC MIXIN input frequency fMIXIN Operating temperature TA Page 3 Unit min. typ. max. 1.1 1.35 1.6 V 50 MHz 60 °C –10 25 May 2000 RX3140 the wireless IC company Electrical Characteristics (VCC = 1.4 V, VSS = 0 V, TA = 25 °C, BS = high unless otherwise noted) Value Parameter Symbol Condition Unit min. Quiescent current consumption Standby current consumption Mixer conversion gain ICC,total ICC,standby VBS = 0 V GC measured after 455 KHz ceramic filter 9 typ. max. 1.1 1.6 mA 5 µA 16 dB 12.5 Mixer output intermodulation intercept point OIP3 –10 dBm Mixer input resistance Rin,MIX 5 KΩ Mixer output resistance Rout,MIX 2 KΩ IF amplifier input resistance Rin,IF 2 KΩ S/N ratio 1 SN1 –53 dBm at MIXIN 63 dB S/N ratio 2 SN2 –53 dBm at IFIN 63 dB S/N ratio 3 SN3 –91 dBm at IFIN 25 dB Demodulation output level VOD –53 dBm at IFIN 45 mVrms AM rejection ratio AMR –53 dBm at IFIN, AM=30 % 50 dB FSK output duty ratio Low battery alarm threshold voltage Regulator output voltage Charging/discharging current DR 40 50 60 % VALM 1.05 1.1 1.15 V VREGOUT 430 Ω load resistor 0.95 1.0 1.05 V ICH VFSKREF = 0 V, VLPFOUT = 0.18 V 35 70 110 µA ALM logic HIGH output current IOH,ALM 2 µA ALM logic LOW output voltage VOL,ALM 0.4 V FSKOUT logic HIGH output current IOH,FSK- 2 µA FSKOUT logic LOW output voltage VOL,FSK- 0.4 V Revision B OUT OUT Page 4 May 2000 RX3140 the wireless IC company Functional Description The RX3140 IF receiver IC incorporates a mixer, crystal-based local oscillator, IF amplifier, quadrature FM demodulator, bit-rate filter, and 1-bit comparator and is capable of demodulating 2-level FSK input signals. In addition, 1.0 V regulator and 1.1 V low battery alarm functions are provided. Power-down Function The entire receiver IC may be powered up and down through the control of the BS input (pin 13). During power down operation, the quiescent current consumption of the IC drops to approximately 0 µA. The high input impedance of the BS pin allows for direct interfacing with the CMOS output of an off-chip microcontroller. Charge/Discharge Circuitry The function of the charge/discharge circuitry is for both fast and slow charging/discharging of the capacitor used for storing the voltage reference level of the FSKREF pin. The CHARGE input (pin 14) should be enabled (CHARGE = high = fast charge) immediately after transition of the receiver IC from power-down to normal operation in order to reduce the charging/discharging time for coarse adjustment of the FSKREF voltage to the appropriate dc level (i.e. dc level of the LPFOUT pin) and consequently to minimize the erroneous output of the 1-bit comparator. During actual data reception, the CHARGE pin should be set to low (CHARGE = low = slow charge) for fine adjustment of the FSKREF voltage. 1-bit Comparator The integrated 1-bit comparator operates as a data slicer and “squares up” the bit-rate filtered output from the quadrature demodulator. The decision threshold voltage level for the 1-bit comparator is stored on an external capacitor connected to the FSKREF pin. Regulator The on-chip 1.0 V regulator requires a suitable off-chip PNP transistor to achieve regulation. The external PNP transistor should have an hFE > 200 for VCE ≥ 0.1 V . Low Battery Alarm The low battery alarm output, ALM, is normally low, but rises to 1.1 V (≈ VCC) when the VCC voltage falls below approximately 1.1 V. Revision B Page 5 May 2000 RX3140 the wireless IC company Typical Performance Characteristics $ P & & , % G ' 2 9 9&& 9 7 . &+$5*( + 9&& 9 7 . ,),1 G%P IPRG +] ∆I .+] G% P9SNSN 9&&9 ,),1.+] 9 1 , ) 3 / 9 0 / $ 9&& 9 7 . ,) G%P IPRG +] ∆I .+] 9&&9 ,),1.+] µ $ ( * 5 $ + & , 9&& 9 7 . Revision B )6.5()9 Page 6 May 2000 RX3140 the wireless IC company Test Circuit VREGOUT 19 MIX IN VSS 18 REG OUT 17 REG CON 16 ALM 15 FSK OUT 14 LOW 1-BIT BATTERY COMPARATOR ALARM 1.0 V REGULATOR CHA RGE 13 12 BS LPF OUT 11 68 KΩ 0.01 µF 20 330 pF 68 KΩ 560 pF 68 KΩ VOD 100 KΩ 100 KΩ 2SA1015GR 430 Ω 2.2 µF 1 nF VFSKOUT VCC 51 Ω VALM LPF IN CHARGE/ DISCHARGE CIRCUIT MIXER QUAD DETECTOR OSCILLATOR IFAMP 4 39 pF 10 µF 22 KΩ 0.1 µF 56 pF 5 6 GC MURATA CFVM455E Revision B Page 7 7 8 22 pF AF OUT QUAD 9 10 3.3 KΩ 3 IF OUT FSK REF DEC 10 µF 2 IFIN 10 µF 1 VCC VCC VCC MIX OUT 0.1 µF OSC OUT OSC IN VCC May 2000 RX3140 the wireless IC company Application Circuit LNA 1st mixer OSCIN 1st IF amplifier MIXIN OSCOUT VSS MIXOUT REGOUT IFIN DEC FSKREF IFOUT Frequency multiplier (×2,3) QUAD +07 VCC REGCON ALM FSKOUT CHARGE BS LPFOUT AFOUT LPFIN 1st LO XIN TEST XOUT DB DO VSS FIN +07 VDD2 RAM ROM CPU Decoder NC VDD1 OPR LE DATA CLK LD NC LCD driver Driver LCD DC/DC converter Revision B Page 8 May 2000