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ST7537HS1
HOME AUTOMATION MODEM
. . . . . . . . . . .
HALF DUPLEX ASYNCHRONOUS 2400bps FSK MODEM Tx CARRIER FREQUENCY SYNTHESIZED FROM EXTERNAL CRYSTAL LOW DISTORTION Tx SIGNAL Rx SENSITIVITY BETTER THAN 1mVRMS CARRIER DETECTION WATCH-DOG INPUT RESET AND MASTER CLOCK OUTPUTS FOR MICROCONTROLLER POWER AMPLIFIER BIAS CURRENT CONTROL (HIGH IMPEDANCE IN Rx MODE) SIMPLE AND ECONOMICAL APPLICATION SCHEMATICS COMPATIBLE WITH CENELEC EN 50065-1 AND FCC SPECIFICATION CARRIER DETECT CLAMPING ON RxD PROGRAMMABLE (ALLOWING DEMODULATION ON VERY LOW RECEIVE LEVEL, 1mVRMS TYPICALLY)
PLCC28 (Plastic Chip Carrier) ORDER CODE : ST7537HS1
PIN CONNECTIONS
RxFO
AV DD
VCM
RAI
DEMI
SS
4
3
2
1
28
27
26 25 24
TxIFI
5
6 7
IFO
AV
DVCC
DESCRIPTION The ST7537HS1 is a half duplex asynchronous FSK MODEM designed for home automation communication on the domestic electric mains which complies with the EN 50065-1 CENELEC standard. It mainly operates from a 10V power supply and a 5V power supply for the microcontroller digital interface. It is interfaced to the power line by an external driver, and a transformer (see Application Schematic Diagram). Its data transmission rate is 2400 bps and its carrier frequency is 132.45kHz.
June 1995
PAFB
ATO PABC
RSTO
RxD TxD
23 22 21
20 19 13 15 16 12 14 17 18
8 9
10 11
PABC TEST1 TEST2
CD Rx/Tx WD
TEST3
TEST4
XTAL1
DV DD
XTAL2
MCLK
SS
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7537H-01.EPS
DV
ST7537HS1
PIN DESCRIPTION
Pin Name VCM AVDD RAI RxFO TxIFI PAFB ATO PABC PABC TEST1 TEST2 TEST3 TEST4 DVDD DVSS XTAL1 XTAL2 MCLK WD Rx/Tx CD TxD RxD RSTO DVCC IFO DEMI AVSS Pin Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Pin Type Analog Supply Analog Analog Analog Analog Analog Digital (10V) Digital (10V) Digital Digital Digital Digital Supply Supply Digital (10V) Digital (10V) Digital Digital Digital Digital Digital Digital Digital Supply Analog Analog Supply Common Mode Voltage Analog Power Supply : 10V 5 % Receive Analog Input Receive Filter Output Transmit and Intermediate Frequency Filters Test Input (mode TEST3) Power Amplifier Feed-back Input Analog Transmit Output Power Amplifier Bias Current Control Complementary Output Power Amplifier Bias Current Control Output Tx to Rx Automatic Mode Switching Control Input Automatic Mode Switching Time and Watch-dog Time Reduction Control Input TxIFI Selection Input Undelayed Reset Input Digital Power Supply : 10V 5% Digital Ground : 0V Crystal Oscillator Input Crystal Oscillator Output Master Clock Output Watch-dog Input Rx or Tx Mode Selection Input Carrier Detect Output Transmit Data Input Receive Data Output Reset Output Digital Buffers Supply Voltage : 5V 5 % Demodulator Input Analog Ground : 0V
7537H-01.TBL
Description
Intermediate Frequency Filter Output
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ST7537HS1
BLOCK DIAGRAM
AV DD DV DD AV SS DV SS V CM DV CC
2
14
28
20dB GAIN
15
A.A. FILTER
1
25
A.A. FILTER
SMT. FILTER
RAI
3
Rx BAND-PASS S.C. FILTER
I.F. BAND-PASS S.C. FILTER
SMT. FILTER
MUX
26 IFO
CONTROL LOGIC TIME BASE RESET LOGIC
RxFO
4
CARRIER DETECTION REFERENCE VOLTAGE
17 XTAL2 16 XTAL1 18 MCLK 19 WD 24 RSTO
20 Rx/Tx
CD 21
OUTPUT AMPLIFIER
SMT. FILTER
ATO PAFB PABC PABC
7 6 9 8
A.A. FILTER
MUX
Tx BAND-PASS S.C. FILTER
FSK MODULATOR
22 TxD 5 TxIFI
RxD 23
TEST LOGIC
POST-DEMO S.C. FILTER
CORRELATOR
27 DEMI
FSK DEMODULATOR
ST7537HS1
10 TEST1 11 TEST2 12 TEST3 13 TEST4
TRANSMIT SECTION The transmit mode is set when Rx/Tx = 0, if Rx/Tx is held at 0 longer than 1 second, then the device switches automatically in the Rx mode. A new activation of the Tx mode requires Rx/Tx to be returned to 1 for a minimum 2 microsecond period before being set to 0. The Transmit Data (TxD) enter asynchronously the FSK modulator with a nominal intra-message data rate of 2400 bps. The basic transmit frequencies are : - f(TxD=0) = 133.05kHz - f(TxD=1) = 131.85kHz These frequencies are synthesized from a 11.0592MHz crystal oscillator; their precision is the same as the crystal one's (100ppm). The modulated signal coming out of the FSK modulator is filtered by a switched-capacitor band-pass filter (Tx band-pass) in order to limit the output spectrum and to reduce the level of harmonic components. The final stage of the Tx path consists of an operational amplifier which needs a feed-back signal (PAFB) from the power amplifier as shown on Application Schematic Diagram. In Tx mode the Receive Data (RxD) signal is set to 1.
RECEIVE SECTION The receive section is active when Rx/Tx = 1. The Rx signal is applied on RAI and filtered by a band-pass switched capacitor filter (Rx band-pass) centered on the carrier frequency and whose bandwidth is around 12kHz. The Rx filter output is amplified by a 20dB gain stage which provides symetrical limitations for large voltage. The resulting signal is down-converted by a mixer which receives a local oscillator synthesized by the FSK modulator block. Finally an intermediate frequency band-pass filter (IF bandpass) whose central frequency is 5.4kHz improves the signal to noise ratio before entering the FSK demodulator. The coupling of the intermediate frequency filter output (IFO) to the FSK demodulator input (DEMI) is made by an external capacitor C5 (100nF 10%, 10V) which cancels the Rx path offset voltage. The RxD output delivers the demodulated signal if the carrier detect (CD) signal is low and is set to high level when CD = 1. The RxD output can delivers the demodulated signal whatever the level of CD (0 or 1) if Rx/Tx = 1 and TxD = 0 (see Figure 1).
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7537H-02.EPS
ST7537HS1
Figure 1 : Data Timing Chart
Rx/Tx CD
7537H-03.EPS
TxD RxD
DATA DATA
ADDITIONAL DIGITAL AND ANALOG FUNCTIONS Time base A time base section delivers all the internal clocks from a crystal oscillator (11.0592MHz). The crystal is connected between XTAL1 and XTAL2 pins and needs two external capacitors C3 and C4 (22pF 10%, 10V) for proper operation. Reset and watch-dog The reset output (RSTO) is driven high when the supply voltage is lower than Vrh (typically 7.6V) with an hysteresis Vrh-Vrl (typically 300mV) or when no negative transition occurs on the watch-dog input (WD) for more than 1.5 second (see the timing chart on Figure 2). When a reset occurs RSTO is held high for at least 50ms. Signal detection The Carrier Detect output (CD) is driven low when the input signal amplitude on RAI is greater than VCD for at least TCD (typically 6ms see the timing chart on Figure 3). When the input signal desappears or becomes lower than VCD, CD is held low for at least Tcd before returning to a high level. VCD is the carrier detection threshold voltage which is set internally to detect 5mVRMS typically. External power amplifier bias control Two dedicated digital output (PABC and PABC) delivering a signal between 0V and 10V are driven
low respectively high, when the circuit is set in the receive mode (Rx/Tx=1) or when the transmit mode time out (1 second) is exceeded; in the same time the output ATO is put in a high impedance state. TESTING FEATURES - An additionnal amplifier allows the observation of the Rx band-pass filter output on pin RxFO. - A direct input to the Tx band-pass filter and to the IF filter (TxIFI) is selected when TEST3 = 1. - The 1 second normal duration of the Tx to Rx mode automatic switching is reduced to 488s and the 1.5 second watch-dog time out is reduced to 46.3s when TEST2 = 1. - When TEST1 = 1 the Tx to Rx mode automatic switching is desactivated and the functional mode of the circuit is fully controlled by Rx/Tx. - TEST4 is a reset input which allows an undelayed control of RSTO and of the internal state of the circuit. POWER SUPPLIES WIRING PRECAUTIONS The ST7537HS1 has two positive power supply terminals (AVDD,DVDD) and two ground terminals (AVSS,DVSS) in order to separate internal analog and digital supplies. The analog and digital terminals of each supply pair must be connected together externally for proper operation. The VDD must be protected against short-circuit for proper operation.
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ST7537HS1
ABSOLUTE MAXIMUM RATINGS
Symbol AVDD/DVDD VI VO VO IO VI VO IO PD Toper Tstg
Notes : 1. 2.
Parameter Supply Voltage (1) Digital Input Voltage Digital Output Voltage (microcontroller interface) Digital Output Voltage (PABC and PABC) Digital Output Current Analog Input Voltage Analog Output Voltage Analog Output Current Power Dissipation Operating Temperature Storage Temperature
Value - 0.3, + 12 DVSS - 0.3, DVDD + 0.3 DVSS - 0.3, DVCC + 0.3 DVSS - 0.3, DVDD + 0.3 - 5, + 5 AVSS - 0.3, AVDD + 0.3 AVSS - 0.3, AVDD + 0.3 - 5, + 5 500 0, + 70 - 55, + 150
Unit V V V V mA V V mA
o o
C C
The voltages are referenced to AVSS and DVSS. Absolute maximum ratings are values beyond which damage to device may occur. Functional operation under these conditions is not implied.
GENERAL ELECTRICAL CHARACTERISTICS (A/DVDD = 10V, A/DVSS = 0V, DVCC = 5V and 0oC Tamb 70oC, unless otherwise specificied)
Symbol AVDD DVDD AIDD + DIDD DVCC DICC VIH VIL VOH Parameter Supply Voltage Supply Current Digital Output Supply Voltage Digital Output Supply Current High Level Input Voltage Low Level Input Voltage High Level Output Voltage Digital Inputs Digital Inputs IOH = -100A * Digital Outputs * Digital Outputs PABC and PABC 4.9 9.8 0.1 0.2 40 60 4.2 0.8 4.75 1.5 Test Conditions Min. 9.5 Typ. 10 30 5.25 Max. 10.5 Unit V mA V mA V V V V V V %
7537H-03.TBL 7537H-04.TBL
VOL
Low Level Output Voltage
* Digital Outputs * Digital Outputs PABC and PABC
MCLK Output, CL = 15pF
IOL = 100A
DC
Duty Cycle
TRANSMITTER ELECTRICAL CHARACTERISTICS (A/DVDD = 10V, A/DVSS = 0V, DVCC = 5V and 0oC Tamb 70oC, unless otherwise specificied)
Symbol VTAC HD2 HD3 FD Parameter Max Carrier Output AC Voltage Second Harmonic Distortion Third Harmonic Distortion FSK Peak-to-peak Deviation Test Conditions RL = 5.6k RL(AVSS) = 5.6k R(ATO, PAFB) = 1k Min. 0.8 Typ. 1.0 - 50 - 60 1200 Max. 1.3 Unit VRMS dB dB Hz
5/9
7537H-02.TBL
mW
ST7537HS1
RECEIVER ELECTRICAL CHARACTERISTICS (A/DVDD = 10V, A/DVSS = 0V, DVCC = 5V and 0oC Tamb 70oC, unless otherwise specificied)
Symbol VIN VIN RIN GRx BER tDEM VCD Parameter Input Sensitivity Maximum Input Signal Input Impedance Receive Gain Bit Error Rate (1) Demodulation Time Carrier Detection Level f = 132.45kHz S/N = 15dB, S = 10mVRMS, N : white Alternate 0 , 1 sequence f = 132.45kHz, sine wave 15 20 10-5 3 5 10 10-3 T bit mVRMS Test Conditions Min. Typ. 1 Max. 10 2 Unit mVRMS VRMS k dB
7537H-05.TBL 7537H-05.EPS 7537H-04.EPS 7537H-06.TBL
Note 1 : This parameter is guaranteed by correlation
ADDITIONAL DIGITAL AND ANALOG FUNCTIONS ELECTRICAL CHARACTERISTICS (A/DVDD = 10V, A/DVSS = 0V, DVCC = 5V and 0oC Tamb 70oC, unless otherwise specificied)
Symbol VRH VRL tRST tWD tWM tOUT tCD Parameter High Level Reset Voltage Low Level Reset Voltage Reset Time Watch-dog Pulse Width Watch-dog Pulse Period Watch-dog Time Out Carrier Detection Time Test Conditions See Figure 2 See Figure 2 See Figure 2 See Figure 2 See Figure 2 See Figure 2 See Figure 3 3 50 500 800 1.5 6.5 Min. Typ. 7.9 7.6 Max. Unit V V ms ns s s ms
Figure 2 : Reset and Watch-dog Timing Chart
VRH DV DD t RST t OUT t RST VRL
RSTO t WD WD t WM
Figure 3 : Carrier Detection Timing Chart
VC D
RAI
t CD
t CD
CD
6/9
ST7537HS1
FILTER TEMPLATES Receive and Transmit Filter
Frequency (kHz) 92 126.45 Ref 132.45 138.45 180 Min. -5 -5 Gain (dB) Typ. -3 0 -3 Max. - 30 -2 -2 - 30
Intermediate FrequencyFilter
Frequency (kHz) 2.4 4.3 Ref 5.4 6.5 11.6 Min. -4 -5 Gain (dB) Typ. -3 0 -3 Max. - 35 -1 -2 - 35
7537H-07.TBL
APPLICATION SCHEMATIC INFORMATIONS
RESISTORS R1 R2 R3 R4 R5 R6 R7 R8 R9 R11 L1 180 2.2 2.2 2.2 2.2 180 47k 1k 1k 47k INDUCTOR 10H TRANSISTORS Q1 : 2N2907 Q2 : 2N2222 Q3 : 2N2222 Q4 : 2N2907 Q5 : 2N2907 Q6 : 2N2222
Notes : 1. 2.
CAPACITORS C1 C2 C3 (2) C4 (2) C5 C6 C7 C8 5% C9 C10 C11 (1) 1.5 C12 (1) 1F 470nF 22pF 22pF 100nF 6.8nF 100nF 2.2F 100nF 2.2F 100nF 100nF Ceramic 10V Ceramic 10V TRANSIL TRL1 : SGS-THOMSON P6KE6V8CP TRANSFORMER CRYSTAL QTZ1 : 11.0592MHz parallel resonance
7537H-08.TBL
Ceramic 50 Paper, class X2 10% 10% 10% 5% Ceramic 10V Ceramic 10V Ceramic 10V Plastic Film 50V Ceramic 10V Ceramic 10V
TR1 : TOKO T1002 N
These capacitors might not be necessary if the overall power supplies decoupling is sufficient. The value of these capacitors depends on the crystal parameters.
7/9
ST7537HS1
APPLICATION SCHEMATIC DIAGRAM
+10V C7 Q5 Thermal coupling
C8 C5 C10
R11
R1 Q2
14 C9 1
2
27 DEMI
26 IFO R9 RAI PAFB 3 6 7 8 9 4 R5 TEST1 10 TEST2 11 TEST3 12 TEST4 13 R6 C6 C2 Q4 R4 L1 Q3 C1 R8 Q1 C11 R3 R2
AVDD DVDD VCM
18 MCLK
19 WD 20 Rx/Tx 21 CD 22 TxD 23 RxD 24 RSTO
S T 7 5 3 7 H S 1
ATO PABC PABC RxFO
MICROCONTROLLER INTERFACE
5V
25 DV CC AVSS DV SS 28 15 XTAL1 16 QTZ1
TXIFI XTAL2 17
5
R7 MAINS 50/60Hz
C12
C3
C4
Q6
0V
8/9
7537H-06.EPS
Thermal coupling
TRL1
ST7537HS1
PACKAGE MECHANICAL DATA 28 PINS - PLASTIC CHIP CARRIER
B M1
4 2 1 28 26
M
M1
E
e3
11 12
19 18
G (Seating Plane Coplanarity)
Dimensions A B D D1 D2 E e e3 F F1 G M M1 Millimeters Typ.
D
Inches Typ.
Min. 12.32 11.43 4.2 2.29 0.51 9.91
Max. 12.57 11.58 4.57 3.04 10.92
Min. 0.485 0.450 0.165 0.090 0.020 0.390
Max. 0.495 0.456 0.180 0.120 0.430
1.27 7.62 0.46 0.71 0.101 1.24 1.143
0.050 0.300 0.018 0.028 0.049 0.045
PLCC28.TBL
0.004
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No licence is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectronics. (c) 1995 SGS-THOMSON Microelectronics - All Rights Reserved Purchase of I2C Components of SGS-THOMSON Microelectronics, conveys a license under the Philips I2C Patent. Rights to use these components in a I2C system, is granted provided that the system conforms to the I2C Standard Specifications as defined by Philips. SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - China - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco The Netherlands - Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A.
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PMPLCC28.EPS
A
F1
e
F
D2 D1
M
5
25

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