1.3GHZ DUAL PLL S1T8825B INTRODUCTION 16−TSSOP−0044 The S1T8825B is a high performance dual frequency synthesizer with two integrated high frequency pre-scalers for RF operation up to 1.3 GHz. The S1T8825B is composed of modulus pre-scalers providing 64 and 66, no dead-zone PFD, selectable charge pump current, selectable power down mode circuits, lock detector output, and loop filter’s time constant switch. It is fabricated using the ASP5HB Bi-CMOS process and is available 16-TSSOP with surface mount plastic packaging. Serial data is transferred into the S1T8825B via three-wire interface (CK, DATA, EN). FEATURES • Two systems for receiver and transmitter • Very low operating current consumption: Icc = Typ. 7.0mA @ 3.0V • Low operating power supply voltage : 2.2 to 5.5V ( 200MHz to 550MHz Operating ) 2.7 to 3.6V ( 550MHz to 1.3GHz Operating ) • Modulus pre-scaler: 64 / 66 • No dead-zone PFD • Colpitts type local oscillation • Selectable charge pump current • Selectable power down mode • TSSOP 16-pin package (0.65 mm pitch) ORDERING INFORMATION Device Package Operating Temperature +S1T8825B01-R0B0 16−TSSOP−0044 −30 °C to + 85 °C +: New Product APPLICATIONS • Cordless telephone systems • Portable wireless communications (PCS) • Wireless Local Area Networks (WLANs) • Other wireless communication systems 1 S1T8825B 1.3GHZ DUAL PLL BLOCK DIAGRAM Fin1 1 VCC 1/2 Prescaler 1 32, 33 Prescaler 1 32, 33 Buffer Buffer 2 CP1 3 GND 4 LD 5 CK 6 DATA 7 EN Pre_Amp Charge Pump 1/2 2 Channel 1 Programable Divider Channel 2 Programable Divider Lock Detector 6 Control Circuit 17 12 Reference Divider Charge Pump 14 CP2 Phase Detector 13 GND Switch 12 Local OSC 11 OSCI Buffer PIN CONFIGURATION Fin1 1 16 Fin2 VCC 2 15 VCC CP1 3 14 CP2 GND 4 13 GND LD 5 12 SW CK 6 11 OSCI DATA 7 10 OSCO EN 8 9 BO S1T8825B 16TSSOP 2 SW 10 OSCO 1/2 8 KB8825 16 Fin2 15 VCC 2 Phase Detector Pre_Amp 9 BO 1.3GHZ DUAL PLL S1T8825B PIN DESCRIPTION Pin No. Symbol I/O Description 1 Fin1 I Input terminal of channel 1 RF signal. 2, 15 Vcc − Power supply voltage input. PIN2 and PIN15 are connected together. 3 CP1 O Output terminal of channel 1 charge pump. Charge pump is constant current output circuit, and output current is selected by input serial data. 4, 13 GND − Terminal of GND. PIN4 and PIN13 are connected together. 5 LD O Output terminal of lock detection. It is the open drain output. 6 CK I Input terminal of clock. 7 DATA I Input terminal of data. 8 EN I Input terminal of enable signal. 9 BO O Output terminal of buffer amplifier. The signal of local oscillation is output through the buffer amplifier. 10 OSCO O Output terminal of local oscillation signal. 11 OSCI I Input terminal of local oscillation signal. In case of external input, connecting it to this terminal. 12 SW O Switch-over terminal for the time constant of loop filter. It is an open drain output. If you don’t switch the time constant of loop filter, general output is available. 14 CP2 O Output terminal of channel 2 charge pump. Charge pump is a constant current output circuit, and the output current is selected by input serial data. 16 Fin2 I Input terminal of channel 2 RF signal. ABSOLUTE MAXIMUM RATINGS Characteristic Symbol Value Unit Power Supply Voltage Vcc 6 V Power Dissipation PD 600 mW Operating temperature TOPR −30 to + 85 °C Storage temperature TSTG −55 to +150 °C Take care ! ESD sensitive device 3 S1T8825B 1.3GHZ DUAL PLL ELECTRICAL CHARACTERISTICS (Ta = 25°°C, VCC = 3V, unless otherwise specified) Characteristic Symbol Test Conditions Min. Typ. Max. Unit Fin1=Fin2= 200MHz — 550MHz 2.2 3.0 5.5 V Fin1=Fin2= 550MHz — 1.3GHz 2.7 3.0 3.6 V 5.5 7.0 9.5 mA − 0 10 µA 200 − 1300 MHz Vcc=2.2V − 15 − 0 Vcc=3.0V − 15 − 0 Vcc=5.5V − 10 − 0 Vcc=2.2V −15 − 0 Vcc=3.0V −15 − 0 Vcc=5.5V − 10 − 0 Vcc=2.7V − 10 − 0 Vcc=3.0V − 10 − 0 Vcc=3.6V − 10 − 0 5 - 25 Vcc = 2.2V − 10 0 5 Vcc = 3.0V − 10 0 5 Vcc = 5.5V -5 0 5 Vcc = 2.2V − 10 0 5 Vcc = 3.0V − 10 0 5 Vcc = 5.5V −5 0 5 Operating power supply voltage VCC Operating current consumption ICC Fin1=Fin2=1.3GHz/ -5dBm input Standby current ISB Standby mode Fin operating frequency Fin Fin1 = Fin2 = − 5dBm Fin1 = Fin2 = 200MHz Fin input sensitivity Fin Fin1 = Fin2 = 550MHz Fin1 = Fin2 = 1.3GHz OSCI operating frequency Fosc VFin = 0dBm, sinewave fosc = 10MHz OSCI input voltage Vosc fosc = 20MHz dBm MHz dBm Serial data input high voltage (CK, DATA, EN) VIH VCC = 2.2 to 5.5V VCC − 0.4 − - V Serial data input low voltage (CK, DATA, EN) VIL VCC = 2.2 to 5.5V − − 0.4 V Charge pump output current ICP1 CP1 = 0, CP2 = 0 VCP = 1.5 V – ± 1.6 − mA ICP2 CP1 = 1, CP2 = 0 VCP = 1.5V – ± 0.2 − mA ICP3 CP1 = 0, CP2 = 1 VCP = 1.5V − ± 0.4 − mA ICP4 CP1 = 1, CP2 = 1 VCP = 1.5V − ± 0.8 − mA ICPL Standby mode, Vcp = 1.5V −1 − +1 µA Charge pump leakage 4 1.3GHZ DUAL PLL S1T8825B FUNCTIONAL DESCRIPTIONS SERIAL DATA INPUT AND TIMING CK (Pin6), DATA (Pin7), EN (Pin8) terminals in S1T8825B are used for MCU serial data interface (LSB: 1st input data; MSB: Last input data). Serial data controls the programmable reference divider, programmable divider (CH1), programmable divider (CH2), and control latch separately by means of group code. Binary serial data is entered via the DATA pin. One bit of data is shifted into the internal shift register on the rising edge of the clock. When EN pin is high, stored data is latched. The three terminals, CK, DATA, and EN, contain Schmitt trigger circuits to keep the data from errors caused by noise, etc. < Notice > 1. When power supply of S1T8825B is disconnected, CLK, DATA, EN port from MCU should be pulled low. 2. When power goes up first, R counter data should be entered earlier than N1 and N2 counter data. 3. When power goes up first, control data should be entered earlier than N1 and N2 counter data. ≥ 1us CK DATA LSB MSB N1 (R1) ≥ 0.2us ≥ 0.2us ≥ ≥0.2us N2 (R2) MSB LSB N3 (R3) N16 (R11) N17 (R12) GC2 GC1 ≥0.1us ≥ 0.1us LSB MSB EN ≥ 0.2us ≥0.2us Figure 1. NOTE: Start data input with LSB first SERIAL DATA GROUP AND GROUP CODE The S1T8825B can be controlled through 4 kinds of group selection. Each group is identified by selective a 2-bit group code given below. Serial Bits Group Location GC1 (MSB) GC2 (MSB-1) 0 0 Control Latch 0 1 Ch 1 N Latch 1 0 Ch 2 N Latch 1 1 OSC R Latch 5 S1T8825B 1.3GHZ DUAL PLL CONTROL LATCH The control register executes the following functions: • Mode selection (H: test mode, L: normal mode) • Charge pump’s polarity and output current selection for each channel. • Output state selection for Lock Detector. • Standby control of each channel and reference divider. • ON / OFF control in filter switch. LSB T CH1 CP CP1 CH2 CP2 SB1 CP1 MSB CP2 SB2 SBR LD1 LD2 SW GC2 "0" GC1 "0" Group Code Figure 2. Bit Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 Name T CP CP1 CP2 SB1 CP1 CP2 Description test mode charge pump output polarity channel 1 charge pump output current channel 1 charge pump output current channel 1 standby channel 2 charge pump output current channel 2 charge pump output current Bit 10 Bit 11 Bit 12 Bit 13 Bit 14 Bit Bit 8 Bit 9 Name SB2 SBR LD1 LD2 SW GC2 GC1 Description channel 2 standby reference divider standby lock detector control 1 lock detector control 2 filter switch group code “0” group code “0” 6 1.3GHZ DUAL PLL S1T8825B CHARGE PUMP OUTPUT POLARITY (CP) In normal operation, the CP should be “0”. In reverse operation, the CP should be “1”. Depending upon VCO characteristics, CP should be set accordingly; When VCO characteristics are like (1), CP should be set to low When VCO characteristics are like (2), CP should be set to high. VCO Characteristics (1) VCO Output Frequency (2) VCO Input Voltage CHARGE PUMP OUTPUT CURRENT (CP1, CP2) The S1T8825B includes a constant current output type charge pump circuit. Output current is varied according to control bit “CP1” and “CP2”. In order to get high speed lock-up, select the best charge pump output current. Control Bit CP1 CP2 Charge Pump Output Current 0 0 ± 1600 µA 0 1 ± 200 µA 1 0 ± 400 µA 1 1 ± 800 µA 7 S1T8825B 1.3GHZ DUAL PLL TEST MODE AND LOCK DETECTOR OUTPUT (T, LD1, LD2) When T is normal “0”, LD (Pin5) state is varied by controlling “SB1”, “SB2”, “LD1” and “LD2”. When T is high “1”, LD (Pin5) state is changed to be useful for test T SB1 SB2 0 0 1 0 0 1 1 1 0 1 0 8 1 LD1 LD2 LD Output State 0 0 low 0 1 channel2 1 0 channel1 1 1 channel1. AND. channel2 0 0 low 0 1 high 1 0 channel1 1 1 channel1 0 0 low 0 1 channel2 1 0 high 1 1 channel2 0 0 low 0 1 high 1 0 high 1 1 high 0 0 low 0 1 pres2 1 0 fpll2 1 1 fref 0 0 div4 0 1 pres1 1 0 fpll1 1 1 fosc/2 1 1 × × low 0 0 × × low 1.3GHZ DUAL PLL S1T8825B LOCK DETECTOR OUTPUT When the phase comparator detects a phase difference, LD (Pin5) outputs “L”. When the phase comparator locks, LD outputs “H”. On standby, it outputs “H”. When T is less than 2/fosc (T<2 /fosc ) for more than three cycles of reference divider output as in the figure below, the lock detector outputs “H”. A B Reference Divider output Channel Divider output T Charge pump output T<2/fosc Lock detector output Figure 3. Lock Detector Output fosc: OSCI operating frequency (LOCAL OSC). T: time difference of the pulse between reference divider output and channel divider output. A = B = Number of divisions by reference divider fosc 2 fosc (s) (s) PROGRAMMABLE STANDBY MODE (SB1, SB2, SBR) Standby mode can be controlled by 3-control bits such as SB1, SB2 and SBR. SB1 and SB2 can control the standby mode of channel 1 and channel2. The “SBR” bit can do ON / OFF control of reference divider. Control Bit Standby Mode State SB1 SB2 SBR CH1 CH2 REF Mode Status 0 0 × ON ON ON Inter locking Mode 0 1 × ON OFF ON CH1 Locking Mode 1 0 × OFF ON ON CH2 Locking Mode 1 1 0 OFF OFF ON REF On Mode 1 1 1 OFF OFF OFF Standby Mode 9 S1T8825B 1.3GHZ DUAL PLL FILTER SWITCH CONTROL (SW) The operation mode of the SW terminal is set by bit “SW”. SW control is useful for switching the time constant of the loop filter. Output type of this terminal is an open drain output. High lock mode or normal lock mode can be used, taking advantage of filter switch control (SW) with the charge pump output current. When fast lock function can’t be used, normal lock mode is available. Control Bits Operation Mode SW CP1 CP2 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 (SW and LPF example) The third order LPF Normal Lock Mode CP1 R R SW R High Lock Mode GND CRYSTAL OSCILLATOR CIRCUIT (OSCI, OSCO) AND BUFFER OUT (BO) External capacitors C1, C2, C3, and C4 are required to set the proper crystal’s load capacitance and oscillation frequency as shown in figure 4. The value of the capacitors is dependent on the crystal chosen. The BO (Pin9) outputs local oscillation signal with buffer amplifier. This terminal (Pin9) can be applied to the 2nd mixer input C4 1000pF OSCI C1 C3 C2 OSCO OSCO 1000pF BO 1000pF 2'nd MIX or OPEN BO Figure 4. 10 Reference Oscillator OSCI 2'nd MIX or OPEN 1.3GHZ DUAL PLL S1T8825B PROGRAMMABLE REFERENCE COUNTER This block generates the reference frequency for the PLL. The reference divider is composed of 12-bit reference divider and a half fixed divider Sending certain data to the reference divider allows the setting of any of 6 to 8190 divisions (multiple of two) . LSB R1 R2 MSB R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 GC2 "1" Division Ratio of the R counter, R GC1 "1" Group Code R = R1 × 20 + R2 × 21 + … + R12 × 211 Division ratio: 2 × R = 2 × (3 to 4095) = 6 to 8190 Data is shifted in LSB first. Division Ratio R12 R11 R10 R9 R8 R7 R6 R5 R4 R3 R2 R1 3 0 0 0 0 0 0 0 0 0 0 1 1 4 0 0 0 0 0 0 0 0 0 1 0 0 • • • • • • • • • • • • • 4095 1 1 1 1 1 1 1 1 1 1 1 1 Example) A 21.25MHz X-tal oscillator is connected, and divided into 25kHz steps. (Reference frequency is 12.5kHz) 21.25 MHz ÷ 12.5 kHz = 1700 1700 = 2 × R R = (850)10 = (1101010010)2 LSB 0 MSB 1 0 0 1 0 1 0 1 1 0 0 1 1 11 S1T8825B 1.3GHZ DUAL PLL CHANNEL 1, CHANNEL 2 PROGRAMMABLE N COUNTER These programmable dividers are composed of a 5-bit swallow counter (5-bit programmable divider), 12-bit programmable main counter, and two-modulus prescalers providing 64 and 66 divisions. Sending certain data to the swallow counter and the 12-bit programmable main counter allows the setting of any of 2048 to 262142 divisions (multiple of two). The 12-bit programmable divider and swallow counter are set by each channel; each channel is identified by a group code. LSB Swallow counter N1 N2 N3 N4 MSB main counter N5 N6 N7 N8 N9 N10 N11 N12 N13 N14 N15 N16 N17 N18 Division Ratio of the N Counter, N N19 Group Code CH1 = "10" CH2 = "01" Figure 5. 5-BIT SWALLOW COUNTER DIVISION RATIO (A COUNTER) A = N1 × 20 + N2 × 21 … N5 × 24 Division ratio: 0 to 31, B ≥ A Division Ratio (A) N5 N4 N3 N2 N1 0 0 0 0 0 0 1 0 0 0 0 1 • • • • • • 31 1 1 1 1 1 12-BIT MAIN COUNTER DIVISION RATIO (B COUNTER) B = N6 × 20 + N7 × 21 + N7 × 22 … N17× 211 Division ratio: 3 to 4095 Data is shifted in LSB first Division Ratio (B) N17 N16 N15 N14 N13 N12 N11 N10 N9 N8 N7 N6 3 0 0 0 0 0 0 0 0 0 0 1 1 4 0 0 0 0 0 0 0 0 0 0 0 0 • • • • • • • • • • • • • 4095 1 1 1 1 1 1 1 1 1 1 1 1 12 1.3GHZ DUAL PLL S1T8825B Channel1 and 2 Programmable Counter Division Ratio, N N = 2 × (32 × B + A), B ≥ A Division ratio: 192 to 262142 Example) A Signal of 453 MHz is entered into Fin1, and divided into 25 kHz steps. (Reference frequency is 12.5 kHz) 453 MHz ÷ 12.5 kHz = 36240, N = 2 × (32 × B + A) = 36240 , 32 × B + A =18120 N = 18120 ÷ 32 = 566.25, A = 0.25*32 = 8 ∴ B = (566)10 = (1000110110)2, A = (8)10 = (01000)2 LSB MSB 0 0 0 1 0 0 1 1 0 1 1 0 0 0 1 0 0 1 0 Example) A Signal of 462.9 MHz is entered into Fin2, and divided into 25 kHz step. (Reference frequency is 12.5 kHz) 462.9 MHz ÷ 12.5 kHz = 37032, N = 2 × (32 × B + A) = 37032, 32 × B + A =18516 N = 18516 ÷ 32 = 578.625, A = 0.625*32 = 20 ∴ B = (578)10 = (1001000010)2, A = (20)10 = (10100)2 LSB 0 MSB 0 1 0 1 0 1 0 0 0 0 1 0 0 1 0 0 0 1 PHASE DETECTOR AND CHARGE PUMP CHARACTERISTICS Phase difference detection Range: -2 π to +2 π When SW = Low fr fp LD CPO fr > fp fr = fp fr < fp fr < fp fr < fp Figure 6. 13 S1T8825B 1.3GHZ DUAL PLL SENSITIVITY TEST CIRCUIT 2.2 V to 5.5 V 51 ohm RF Signal Generator 50 ohm Microstrip 1000pF 1 Fin1 VCC 2.15 VCC 10 nF 5 5 kohm Oscilloscope 10 uF OSCI 6 7 CK DATA 8 EN 20.945 MHz 11 100p OSCO 10 68p SERIAL DATA UNIT 14 + LD 50p 47p 1.3GHZ DUAL PLL S1T8825B TYPICAL APPLICATION CIRCUIT 10nF VCO 2.2k 50pF 47pF 0.1µF 51k 68p 10nF 2n'd MIX 1nF 8.2k VCC 10nF 20.945 MHz 1nF 100p 16 Fin2 15 VCC 14 CP2 13 GND 12 SW 11 OSCI 10 OSCO 9 BO CLK 6 DATA 7 EN 8 S1T8825B KB8825 Fin1 1 CP1 3 VCC 2 GND 4 LD 5 10nF From 5k 10uF + 1nF 10nF 30k Controller 0.1µF VCC 7.5k VCO 10nF MOD 15 S1T8825B 1.3GHZ DUAL PLL NOTES 16