CXA1999N IF Amplifier for M-ary FSK Pagers Description The CXA1999N is a low current consumption FM IF amplifier which employs the newest bipolar process. It is suitable for M-ary FSK pagers. Features • Low current consumption: 1.16 mA (typ. at VCC = 1.4 V) • Low voltage operation: VCC = 1.1 to 4.0 V • Small package 20-pin SSOP • Second mixer and oscillator • Needless of IF decoupling capacitor • Reference power supply for operational amplifier and comparator • IF input, VCC standard Applications • M-ary FSK pagers • Double conversion pagers 20 pin SSOP (Plastic) Absolute Maximum Ratings • Supply voltage • Operating temperature • Storage temperature • Allowable power dissipation VCC 7.0 V Topr –20 to +75 °C Tstg –65 to +150 °C PD 375 mW Operating Condition Supply voltage VCC1 1.1 to 4.0 V Structure • Bipolar silicon monolithic IC 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— E95517C8Y 1 MIXER MIX IN GND 19 —2— OSC IN 2 LOCAL OSCILLATOR 20 OSC OUT 18 REG OUT 3 MIX OUT REGULATOR Block Diagram and Pin Configuration 4 17 VCC REG CONT LVA OUT 5 IF IN ALARM 16 NRZ OUT 6 IF LIM B.S. NRZ COMPARATOR 15 7 FSK REF QUICK CHARGE CHARGE 14 L.C. OUT 8 QUAD QUAD DET LEVEL COMPARATOR 13 9 DET OUT LPF OUT 12 10 11 RSSI LPF IN CXA1999N CXA1999N Pin Description Pin No. 1 Symbol OSC IN Pin voltage Equivalent circuit Description 1.4 V 15k VCC 300 72 15k 1 2 2 OSC OUT 0.7 V 230 Connects the external parts of crystal oscillator circuit. A capacitor and crystal oscillator are connected to these pins and VCC. GND VCC 1.5k Mixer output. Connect a 455 kHz ceramic filter between this pin and IF IN. 3 3 MIX OUT 1.2 V GND 4 VCC Power supply. 8k 8k 1.5k 5 IF IN 1.4 V VCC 1.5k IF limiter amplifier input. 5 GND 72 6 Controls the battery saving. Setting this pin low suspends the operation of IC. (Applied voltage range: –0.5 V to +7.0 V) 40k 6 B.S. — 140k GND VCC 7 FSK REF 0.2 V Connects the capacitor that determines the low cut-off frequency for the entire system. 72 7 GND —3— CXA1999N Pin No. Symbol Pin voltage Equivalent circuit Description VCC 22k 20k 8 QUAD 1.4 V Connects the phase shifter of FM detector circuit. 8 20p GND VCC 50p 9 DET OUT 0.2 V FM detector output. 9 72 55k GND VCC 7k 10 RSSI 0V 7k RSSI circuit output. 10 70k GND VCC 11 LPF IN 0.2 V Operational amplifier input. 11 72 GND VCC Level comparator and NRZ comparator inputs. Output for operational amplifier is connected. 72 12 LPF OUT 0.2 V 12 72 GND —4— CXA1999N Pin No. Symbol Pin voltage Equivalent circuit 72 13 13 15 16 L.C. OUT NRZ OUT LVA OUT — — — Description 15 16 GND 20k 14 14 CHARGE 0V 100k GND Level comparator, NRZ comparator and LVA comparator outputs. They are open collectors. (Applied voltage range: –0.5 V to +7.0 V) Controls the ON/OFF operation of the quick-charge circuit. Set this pin high to execute the quick charge. (Applied voltage range: –0.5 V to +7.0 V) VCC 17 REG CONT — Output for internal constantvoltage source amplifier. Connect the base of PNP transistor. (Current capacity: 100 µA) 17 72 GND VCC 18 REG OUT 1.0 V Constant-voltage source output. Controlled to maintain 1.0 V. 78k 18 1k 22k GND 19 GND — Ground 4.16k 4.16k VCC 2k 20 MIX IN 1.4 V Mixer input. 20 GND —5— CXA1999N Electrical Characteristics (VCC = 1.4 V, Ta = 25 °C, Fs = 21.7 MHz, FMOD = 1.6 kHz, FDEV = 4.8 kHz, AMMOD = 30 %) Item Symbol Current consumption ICC Current consumption ICCS AM rejection ratio Op amp. input bias current Op amp. maximum output level AMRR IBIAS VO NRZ output saturation voltage VSATNRZ NRZ output leak current ILNRZ NRZ hysteresis width VTWNRZ VB output current VB output saturation voltage REG OUT voltage IOUT VSATVB VREG LVA operating voltage VLVA LVA output leak current LVA output saturation voltage Detector output voltage Logic input voltage high level Logic input voltage low level Limiting sensitivity Level comparator output saturation voltage Level comparator output leak current RSSI output offset Mixer input resistance Mixer output resistance IF limiter input resistance ILLVA VSATLVA VODET VTHBSV VTLBSV VIN (LIM) Conditions Measurement circuit 1 V2 = 1.0 V Measurement circuit 1, V2 = 0 V Measurement circuit 3 30k LPF Measurement circuit 2 Measurement circuit 4 Measurement circuit 6 Vin = 0.3 V Measurement circuit 5 Vin = 0.1 V Measurement circuit 5 Vin = 0.1 to 0.3 V Measurement circuit 7 Measurement circuit 7 Output current 0 µA Measurement circuit 8 V1 = 1.4 to 1.0 V Measurement circuit 8 V1 = 1.0 V Measurement circuit 9 Measurement circuit 3 — — Measurement circuit 3 VSATLC Measurement circuit 11 — — 0.4 V ILLC Measurement circuit 10 — — 5.0 µA VORSSI RINLIM ROUTMIX RINLIM Measurement circuit 12 — — — — 1.6 1.2 1.2 400 2.0 1.5 1.5 550 2.4 1.8 1.8 mV kΩ kΩ kΩ —6— Min. Typ. Max. Unit 0.8 1.16 1.5 mA — 6 20 µA 25 — 160 — — — — 100 — dB nA mVp-p — — 0.4 V — — 5.0 µA — 10 20 mV 100 — 0.89 — — 0.96 — 0.4 1.04 µA V V 1.00 1.05 1.10 V — — 38 0.9 — — — — 50 — — 5 5.0 0.4 68 — 0.35 14 µA V mVrms V V dBµ —7— 3 2 1 A 4 V2 6 15 7 14 8 13 9 12 10 11 1.0V V2 6 7 14 8 13 9 12 10 11 Vin V3 Measurement circuit 4 5 15 V 0.2V Measurement circuit 1 16 1.4V V1 4 5 16 1.4V V1 17 17 VCC 18 VCC 3 19 2 1 18 20 19 20 2 1 1 20 19 20 2 19 5 16 5 16 8 13 9 12 10 11 6 7 14 V 1.0V V2 15 A 8 13 9 12 10 11 Vin Measurement circuit 5 1.4V V1 4 17 7 14 1.0V GND V2 6 15 Measurement circuit 2 1.4V GND V1 4 17 VCC 3 18 VCC 3 18 A V3 GND 0.2V 2 19 1 2 19 22p 20 1 20 1.8µ 4 3 3 4 17 5 1.0V V2 6 15 7 14 V3 10 V 9 8 11 12 13 0.2V 7 14 8 13 9 12 10 11 Vin Measurement circuit 6 1.0V V2 6 15 50µA Measurement circuit 3 16 V 1.4V VCC V1 18 5 16 1.4V VCC V1 17 18 15p 10p to 120p 0.01µ Vin 1µ GND 100k 4.7k Electrical Characteristics Measurement Circuit CXA1999N —8— 19 2 1 2 1 20 19 20 4 3 VCC 3 18 5 16 V 6 7 14 1.0V GND V2 15 8 13 9 12 8 13 9 12 V Measurement circuit 10 1.0V 7 1.4V 6 14 V2 5 4 15 V1 16 17 A Measurement circuit 7 1.4V GND VCC V1 17 100µA 18 V3 0.5V 100k 10 11 Vin 0.2V 10 11 1 20 1 20 2 19 2 19 4 3 VCC 3 18 5 16 6 15 V 7 14 V3 8 13 0.2V 9 12 10 11 7 14 1.0V V2 6 15 V 8 13 9 12 10 11 Vin 50µA 0.1V Measurement circuit 11 1.4V V1 4 17 5 16 100k Measurement circuit 8 VCC V1 17 18 A 19 2 1 2 19 20 1 20 3 4 5 16 1.4V V1 4 5 V2 7 14 8 13 9 12 10 11 7 14 8 13 9 12 V 10 11 Measurement circuit 12 1.0V V2 6 15 Measurement circuit 9 1.0V 6 15 50µA 16 1.4V V1 17 17 VCC 18 VCC 3 18 V CXA1999N 1.8µ 10P to 120P 1 MIXER MIX IN —9— 2 OSC OUT 15P GND REG OUT 3 MIX OUT REGULATOR 18 REG OUT VCC VCC VCC REG CONT CFW455D 4 17 0.01µ 220 5 100k 15 NRZ OUT NRZ OUT 6 IF LIM B.S NRZ COMPARATOR IF IN ALM ALARM 16 100k ALARM 7 L.C. OUT 8 9 560P 100P LPF OUT 2200P DET OUT 12 VCC 4.7k QUAD QUAD DET LEVEL COMPARATOR 13 CDBM 455C28 1µ FSK REF QUICK CHARGE CHARGE 14 100k COMP OUT 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. 22P OSC IN 10µ 19 LOCAL OSCILLATOR 20 0.01µ Application Circuit 10 11 RSSI RSSI LPF IN 39k 39k 39k 1200P CXA1999N CXA1999N Application Note 1) Power Supply The CXA1999N, with built-in regulator, is designed to permit stable operation at wide range of supply voltage from 1.1 to 4.0 V. Decouple the wiring to VCC (Pin 4) as close to the pin as possible. 2) Oscillator Input Oscillator input method a) Using Pins 1 and 2, input self-excited oscillation signal through the composition of a Colpitts type crystal oscillator circuit. b) Directly input a local oscillation signal to Pin 1. 1 2 1 3 Ceramic filter VCC 2 From local signal 3 Ceramic filter Fig. 1 3) Mixer The mixer is of double-balance type. Pin 20 is the input pin. Input though a suitable matching circuit. The input impedance is 2.0 kΩ. Pin 3 serves as the output pin for the mixer, and a load resistance of 1.5 kΩ is incorporated. 4) IF Filter The filter to be connected between this mixer output and the IF limiter amplifier input should have the following specifications. I/O impedance : 1.5 kΩ ±10 % Band width : Changes according to applications. 5) IF Limiter Amplifier The gain of this IF limiter amplifier is approximately 100 dB. Take notice of the following points in making connection to the IF limiter amplifier input pin (Pin 5). a) Be sure to wire to the IF limiter amplifier input (Pin 5) is as short as possible. b) As the IF limiter amplifier output appears at QUAD (Pin 8), be sure to wire to the ceramic discriminator connected to QUAD is as short as possible and reduce the interference with the mixer output and IF limiter amplifier input. 3 4 5 6 7 8 VCC Shortest possible wirings which must be apart as far as possible As short as possible Fig. 2 —10— 9 CXA1999N 6) Quick Charge In order to hasten the rising time from when power is turned on, the CXA1999N features a quick charge circuit. Therefore, the quick charge circuit eliminates the need to insert a capacitor between the detector output and the LPF as is the case with conventional ICs, but connects a capacitor to Pin 7 to determine the average signal level during steady-state reception. The capacitance of the capacitor connected to Pin 7 should be chosen such that the voltage does not vary much due to discharge during battery saving. Connect a signal for controlling the quick charge circuit to Pin 14. Setting this pin high enables the quick charge mode, and setting this pin low enables the steady-state reception mode. Quick charge is used when the power supply is turned on. The battery saving must be set high at the time. Connect Pin 14 to GND when quick charge is not being used. Timing Power supply (Pin number 4) Quick charge (Pin number 14) H Battery save (Pin number 6) H L L active battery saving Fig. 3 7) Detector The detector is of quadrature type. To perform phase shift, connect a ceramic discriminator to Pin 8. The phase shifting capacitor for the quadrature detector is incorporated. The demodulated FM (FSK) signal with the detector will be output to DET OUT (Pin 9) through the internal primary LPF. DET OUT output impedance is 200 Ω or less. The DET OUT output is the anti-phase output to NRZ OUT. The CDBM455C28 (MURATA MFG. CO., LTD.) ceramic discriminator is recommended for the CXA1999N. 7 8 9 DET OUTPUT 4.7k Ceramic discriminator CDBM455C28 VCC —11— CXA1999N 8) Filter Buffer, Level Comparator and NRZ Comparator An operational amplifier for LPF is built in this IC. It is connected internally to the NRZ comparator, level comparator and quick charge circuit. 15 14 13 12 11 L.C. 0.2V 7 Using the operational amplifier of Pins 11 and 12 to construct an LPF, remove noise from the demodulated signal and input the signal to the above three circuits. The level comparator and the NRZ comparator shape waveform of this input signal and output it as a square wave. The comparator output stage is for open collector. Thus, if the CPU is of CMOS type and the supply voltage is different, a direct interface as illustrated in the figure below can be implemented. VCC 1.4V VCC 4 CMOS power supply (15) CMOS IC 13 Comparator output Fig. 6 9) REG CONT Controls the base bias of the external transistors. 10) LVA OUT This pin goes high (open) when the supply voltage becomes low. Since the output is an open collector, it can be used to directly drive CMOS device. The setting voltage of the LVA is 1.05 V (typ.), and it possesses a hysteresis with respect to the supply voltage. The hysteresis width is 50 mV (typ.). 11) B.S. Operation of the CXA1999N can be halted by setting this pin low. This pin can be connected directly to CMOS device. The current consumption for battery saving is 20 µA or less (at 1.4 V). B.S. 6 Fig. 7 —12— CXA1999N 12) M-ary (M = 2- or 4-level) FSK Demodulation System Polarity discrimination output and MSB comparator output are used to demodulate the 4-level waveform shown below. [4-level FSK demodulating waveform] +4.8kHz +1.6kHz –1.6kHz 01 00 10 11 01 10 00 –4.8kHz [NRZ OUT] Polarity discrimination output (When the input frequency is higher than the local frequency) POS 0 0 1 1 0 1 0 1 0 0 1 1 0 0 NEG The polarity can be inverted by setting the local frequency higher than the input frequency. [L.C. OUT] MSB comparator output 1.6kHz 4.8kHz The 4-level FSK demodulating data is divided into an NRZ OUT and L.C. OUT shown above. Here, the NRZ OUT corresponds to a conventional NRZ comparator output. The L.C. OUT is made comparing the demodulated waveform amplitude to the IC internal reference voltage levels. When the threshold value of L.C. OUT is not appropriate to the detector output, the resistance value on Pin 8 should be adjusted for the detector output level adjustment. For the 2-level FSK demodulation, it corresponds to a conventional NRZ comparator output. —13— CXA1999N 13) Principle of Quick Charge Operation BUF in Fig. 8 is the detector buffer amplifier, and AMP is an operational amplifier to construct an LPF. COMP is the level comparator or the NRZ comparator. The CXA1999N has a feedback loop from the comparator input to the input circuit of the detector output buffer. This equalizes the average value of the comparator input voltage to the reference voltage, with the quick charge circuit of CHG being set in the feedback loop. Switching the current of the quick charge circuit enables reduction of the rise time. In this block, CHG is a comparator which compares input voltages and outputs a current based on this comparison. The current on CHG is switched between high and low at Pin 14. When the power is turned on, switch the current to high to increase the charge current at C in Fig. 8 and shorten the time constant. During steady-state reception mode, switch the current to low, lengthening the charge time constant and allowing for stable data retrieval. AMP BUF COMP CHG C Reference voltage Fig. 8 14) S Curve Characteristics Even if the IF IN input signal frequency is deviated, the feedback is applied to the DET OUT operating point so as to match it to the comparator reference voltage by the quick charge operation shown in Fig. 8. Therefore, this feedback must be halted in order to evaluate the S curve characteristics. To execute the evaluation, measure the average voltage on Pin 12 first and input this voltage to Pin 7 from the external power supply. 15) Example of Data Filter Constants C2 R1 R2 R3 C1 Parameter C3 R1 R2 R3 C1 C2 C3 fc (Hz) 512 22 kΩ 22 kΩ 22 kΩ 0.015 µF 0.027 µF 6800 pF 350 1200 68 kΩ 68 kΩ 68 kΩ 2700 pF 4700 pF 820 pF 800 2400 39 kΩ 39 kΩ 39 kΩ 1500 pF 3300 pF 820 pF 1.7 k 3200 (6400)∗ 39 kΩ 39 kΩ 39 kΩ 1200 pF 2200 pF 560 pF 2.3 k bps ∗ For 4 levels Note on operation : Measures for the prevention of electrostatic breakdown should be taken to handle this IC. —14— CXA1999N Example of Representative Characteristics RF input level vs. Audio response, RSSI characteristics for 1.6 kHz SIN signal S+N+D 1000 0 RSSI Audio response (dB) RF 21.7MHz 4.8k Dev. 1.6k AUDIO 20 600 ∗Matching circuit is used LO 30 21.245MHz –10dBm 400 VCC: 1.4V 0dB=50mVrms Data filter 2.3 kHz 40 200 N 50 0 –120 –110 –100 –90 –80 –70 –60 –50 –40 RF input level (dBm) Filter constants of the graph above 2200P 39k 39k 39k 11 DET OUT 1200P 560P —15— 12 LPF OUT fc: 2.3kHz –30 RSSI output voltage (mV) 800 10 CXA1999N Example of Representative Characteristics RF input level vs. Audio response, RSSI characteristics for 600 Hz SIN signal S+N+D 1000 0 RSSI Audio response (dB) RF 20 21.7MHz 4.5kHz Dev. 600Hz AUDIO 600 ∗ Matching circuit is used LO 30 21.245MHz –10dBm 400 0dB=50mVrms Data filter 800 Hz 40 200 N 50 0 –120 –110 –100 –90 –80 –70 –60 –50 RF input level (dBm) Filter constants of the graph above 4700P 68k 68k 68k DET OUT 11 820P 2700P —16— 12 fc: 800Hz –40 –30 RSSI output voltage (mV) 800 10 CXA1999N Supply voltage vs. Current consumption Current consumption (mA) 1.4 1.3 1.2 1.1 1.0 0.9 0.8 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Supply voltage (V) Local input level vs. Mixer gain 20 With IF filter load RF21.7 MHz –60 dBm Matching circuit provided Level difference between Pin 20 and Pin 3 Mixer gain (dB) 10 0 –10 –20 –30 –20 –10 Local input level (dBm) Comparator output voltage (V) Level comparator 1.4 1.0 0.6 0.2 0 170 200 220 250 270 Comparator input voltage (mV) —17— 0 CXA1999N Comparator output voltage (V) NRZ comparator 1.4 1.0 0.6 0.2 0 160 180 200 220 240 Comparator input voltage (mV) 260 280 Detector output level temperature Detector output level (mVrms) 70 60 50 40 30 –25 0 Temperature (°C) Level comparator temperature vs. Threshold level 100 Threshold level -210 mV (mV) : H→L : L→H 50 0 –25 0 25 50 75 25 Temperature (°C) –50 –100 —18— 50 75 CXA1999N Package Outline Unit : mm 20PIN SSOP (PLASTIC) + 0.2 1.25 – 0.1 ∗6.5 ± 0.1 0.1 11 20 1 6.4 ± 0.2 ∗4.4 ± 0.1 A 10 0.65 b (0.15) (0.22) 0.5 ± 0.2 0.1 ± 0.1 DETAIL B : SOLDER b=0.22 ± 0.03 + 0.03 0.15 – 0.01 + 0.1 b=0.22 – 0.05 + 0.05 0.15 – 0.02 0.13 M DETAIL B : PALLADIUM NOTE: Dimension “∗” does not include mold protrusion. 0° to 10° PACKAGE STRUCTURE DETAIL A PACKAGE MATERIAL EPOXY RESIN SONY CODE SSOP-20P-L01 LEAD TREATMENT SOLDER / PALLADIUM PLATING EIAJ CODE SSOP020-P-0044 LEAD MATERIAL 42/COPPER ALLOY PACKAGE MASS 0.1g JEDEC CODE NOTE : PALLADIUM PLATING This product uses S-PdPPF (Sony Spec.-Palladium Pre-Plated Lead Frame). —19—