RX3141 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 RX3141 is a low power IF receiver IC which is fully compatible with the Toshiba TA31145 IC and is suitable for use as the second IF downconverter in double-conversion paging systems. The RX3141 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. In addition, an RSSI voltage output is included as a measure of the received signal strength. Features ! ! ! ! ! ! ! ! ! ! ! Extremely low power operation with power-down feature Built-in crystal oscillator for mixer local oscillator Mixer input frequency: 10 — 50 MHz RSSI function 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 TSSOP-20 package (0.65 mm pitch) Applications ! Pager ! Wireless mouse ! Two-way car alarm system Revision C Page 1 October 2000 RX3141 the wireless IC company Block Diagram and Pin Assignment 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 BS 12 LPF OUT 11 LPF IN CHARGE/ DISCHARGE CIRCUIT MIXER QUAD DETECTOR OSCILLATOR RSSI IFAMP OSC OUT OSC IN 1 Revision C 2 MIX OUT 3 VCC 4 IFIN 5 FSK REF DEC 6 Page 2 7 AF OUT QUAD 8 9 RSSI 10 October 2000 RX3141 the wireless IC company Package and Pin Assignment: 20L, TSSOP OSCIN MIXIN MIXOUT VCC IFIN DEC QUAD AFOUT RSSI Dimensions in mm Date Code FSKREF HiMARK RX3141 OSCOUT VSS REGOUT REGCON ALM FSKOUT CHARGE BS LPFOUT LPFIN Dimensions in inch Symbols Revision C MIN. NOM. MAX. MIN. NOM. MAX. A --- --- 1.20 --- --- 0.048 A1 0.05 --- 0.15 0.002 --- 0.006 A2 0.80 1.00 1.05 0.031 0.039 0.041 b 0.19 --- 0.30 0.007 --- 0.012 C 0.09 --- 0.20 0.004 --- 0.008 D 6.40 6.50 6.60 0.252 0.256 0.260 E --- 6.40 --- --- 0.252 --- E1 4.30 4.40 4.50 0.169 0.173 0.177 e --- 0.65 --- --- 0.026 --- L 0.45 0.60 0.75 0.018 0.024 0.030 y --- --- 0.10 --- --- 0.004 θ 0° --- 8° 0° --- 8° Page 3 October 2000 RX3141 the wireless IC company Pin Descriptions Number Name I/O 1 OSCIN I Oscillator input (base) 2 OSCOUT O Oscillator output (emitter) 3 MIXOUT O Mixer output (2 KΩ output impedance) 4 VCC POWER 5 IFIN I IF amplifier input (2 KΩ input impedance) 6 DEC I IF amplifier de-coupling capacitor connection 7 FSKREF I 1-bit comparator reference input (requires external capacitor) 8 QUAD I Quadrature FM demodulator input 9 AFOUT O Quadrature FM demodulator output 10 RSSI O RSSI voltage output 11 LPFIN I LPF operational amplifier input 12 LPFOUT O LPF operational amplifier output 13 BS I Two-state logic input to control receiver power up/down. (BS = high = normal operation; BS = low = stand-by mode) 14 CHARGE I Two-state logic input to control charge-discharge circuit. (CHARGE = high = fast charge; CHARGE = low = slow charge) 15 FSKOUT O Open collector NRZ comparator output (requires pull-up resistor) 16 ALM O Open collector low battery alarm output (requires pull-up resistor) 17 REGCON O 1.0 V regulator control output for connection to external PNP base 18 REGOUT I 1.0 V regulator input for connection to external PNP collector 19 VSS GND 20 MIXIN I Revision C Description Nominal 1.4 V supply Ground Mixer input (5 KΩ input impedance) Page 4 October 2000 RX3141 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 Revision C Symbol Supply voltage range VCC1 MIXIN input frequency fMIXIN Operating temperature TA Page 5 Unit min. typ. max. 1.1 1.35 1.6 V 50 MHz 60 °C –10 25 October 2000 RX3141 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 ICC,total typ. max. 1.2 1.7 mA 5 µA 16 dB ICC,standby VBS = 0 V Mixer conversion gain GC measured after 455 KHz ceramic filter Mixer input intermodulation intercept point IIP3 –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 Standby current consumption FSK output duty ratio Low battery alarm threshold voltage 9 12.5 DR 40 50 60 % VALM 1.05 1.1 1.15 V VREGOUT 430 Ω load resistor 0.95 1.0 1.05 V RSSI output voltage VRSSI –53 dBm at IFIN 0.45 0.60 0.80 V RSSI output resistance RRSSI Regulator output voltage Charging/discharging current ICH 82 VFSKREF = 0 V, VLPFOUT = 0.18 V 35 70 KΩ 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 C OUT OUT Page 6 October 2000 RX3141 the wireless IC company Functional Description The RX3141 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. RSSI Function A dc potential, which corresponds to the input signal level received at the IFIN input (pin 5), is developed across an internal 82 KΩ resistor. This potential is a measure of the received signal strength and is provided at the RSSI output (pin 10). 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 V CE ≥ 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 C Page 7 October 2000 RX3141 the wireless IC company Typical Performance Characteristics 2 0 1.8 1.6 -5 1.4 VOD (dB) ICC (mA) 1.2 1 0.8 VCC=1.4 V T=300 K CHARGE=H 0.6 0.4 -10 VCC=1.4 V T=300 K IFIN=-53 dBm fmod=600 Hz ∆f=4 KHz 0 dB=158 mVpk-pk -15 0.2 0 0 1 2 -20 440 3 VCC (V) 1.4 0.4 1.2 0.35 450 455 460 IFIN (KHz) LPFIN (V) 0.8 0.6 0.2 VCC=1.4 V T=300 K IF=-53 dBm fmod=600 Hz ∆f=4 KHz 0.15 0.1 0.2 0.05 0 440 0 0 0.5 1 1.5 2 2.5 3 445 450 455 460 465 470 IFIN (KHz) V CC ( V ) 80 1.4 60 1.2 40 µ A) 470 0.25 0.4 I(CHARGE) ( 465 0.3 1 ALM (V) 445 VCC=1.4 V T=300 K MIXIN=21.4 MHz 1 20 0.8 0 -20 0.6 VCC=1.4 V T=300 K -40 0.4 -60 0.2 -80 0 0.1 0.2 0.3 0.4 0.5 0 -110 FSKREF (V) Revision C Page 8 -100 -90 -80 -70 -60 -50 -40 M IX IN (dB m ) -30 -20 -10 0 October 2000 RX3141 the wireless IC company Test Circuit VREGOUT 0.01 µF 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 11 LPF OUT LPF IN 330 pF 68 KΩ 560 pF 68 KΩ 68 KΩ VOD 100 KΩ 100 KΩ 2SA1015GR 430 Ω 2.2 µF 1 nF VFSKOUT VCC 51 Ω VALM CHARGE/ DISCHARGE CIRCUIT MIXER QUAD DETECTOR OSCILLATOR RSSI IFAMP 6 GC MURATA CFVM455E Revision C Page 9 7 8 RSSI 9 10 10 nF 39 pF 10 µF 22 KΩ 0.1 µF 56 pF 5 AF OUT QUAD 3.3 KΩ 4 FSK REF DEC 10 µF 3 IFIN 10 µF 2 VCC VCC VCC 1 MIX OUT 0.1 µF OSC OUT OSC IN VRSSI VCC October 2000 RX3141 the wireless IC company Application Circuit LNA 1st mixer OSCIN 1st IF amplifier MIXIN OSCOUT VSS MIXOUT REGOUT IFIN DEC FSKREF QUAD Frequency multiplier (×2,3) AFOUT RSSI HIMARK RX3141 VCC REGCON ALM FSKOUT CHARGE BS LPFOUT LPFIN 1st LO XIN TEST XOUT DB DO VSS FIN VDD1 HIMARK FS8107E VDD2 RAM ROM CPU Decoder NC OPR LE DATA CLK LD NC LCD driver Driver LCD DC/DC converter Revision C Page 10 October 2000