General features
■ Half-duplex frequency shift keying (FSK)
transceiver
■ Integrated power line driver with programmable
voltage and current control
■ Programmable mains access:
– Synchronous
– Asynchronous
■ Single supply voltage (from 7.5V up to 13.5V)
■ Very low power consumption (I
■ Integrates 5V voltage regulator (up to 50mA)
with short circuit protection
■ Integrated 3.3V voltage regulator (up to 50mA)
with short circuit protection
■ 3.3V or 5V digital supply
■ 8 Programmable transmission frequencies
■ Programmable baud rate up to 4800BPS
■ Receiving sensitivity up to 250 µV
■
Suitable for applications in accordance with EN
50065 Cenelec specification
■ Carrier or preamble detection
■ Band in use detection
■ Programmable control register
■ Watchdog timer
■ 8 or 16 Bit header recognition
■ ST7537 and ST7538 compatible
■ UART/SPI host interface
= 5mA)
q
RMS
ST7540
FSK power line transceiver
HTSSOP28 Exposed Pad
Description
The ST7540 is a Half Duplex
synchronous/asynchronous FSK Modem
designed for power line communication network
applications. It operates from a single supply
voltage and integrates a line driver and two linear
regulators for 5V and 3.3V. The device operation
is controlled by means of an internal register,
programmable through the synchronous serial
interface. Additional functions as watchdog, clock
output, output voltage and current control,
preamble detection, time-out and band in use are
included. Realized in Multipower BCD5
technology that allows to integrate DMOS, Bipolar
and CMOS structures in the same chip.
Order codes
Part number Package Packaging
ST7540 HTSSOP28 (Exposed Pad) Tube
ST7540TR HTSSOP28 (Exposed Pad) Tape and reel
September 2006 Rev 2 1/44
www.st.com
44
Contents ST7540
Contents
1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Pin settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3 Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2 Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.3 Recommended operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5 Crystal resonator and external clock . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6 Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6.1 Carrier frequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6.2 Baud rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6.3 Mark and space frequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.4 ST7540 Mains access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
6.5 Host processor interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.5.1 Communication between Host and ST7540 . . . . . . . . . . . . . . . . . . . . . 20
6.5.2 Control register access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
6.6 Receiving mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6.7 Transmission mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
6.8 Control register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
2/44
ST7540 Contents
7 Auxiliary analog and digital functions . . . . . . . . . . . . . . . . . . . . . . . . . 36
7.1 Band in use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
7.2 Time out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
7.3 Reset & watchdog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
7.4 Output clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
7.5 Output voltage level freeze . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
7.6 Extended control register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
7.7 Under voltage lock out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
7.8 Thermal shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
7.9 5V Voltage regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
7.10 3.3V Voltage regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
7.11 Power-up procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
8 Mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3/44
Block diagram ST7540
1 Block diagram
Figure 1. Block diagram
TEST2
TEST1 BU/THERM
CD/PD
RxD
CLR/T
UART/SPI
REG/DATA
RxTx
TxD
SERIAL
INTERFACE
OSC
X1 WD
X2
CARRIER
DETECTION
PLL
TIME BASE
RSTO MCLK
DIGITAL
FILTER
CONTROL
REGISTER
FSK
MODULATOR
FSK
DEMOD
DAC
TEST
VREG
GND
IF
FILTER
FILTER
V
DD
BU
FILTER
TX
VREG
SV
ALC
PA_IN+
Vdc
SS
AGC
AMPL
CURRENT
CONTROL
VOLTAGE
CONTROL
PA_IN-
FILTER
+
-
PA
RX_IN
CL
Vsense
TX_OUT
CC
V
PA_OUT
V
SS
D03IN1407A
4/44
ST7540 Pin settings
2 Pin settings
2.1 Pin connection
Figure 2. Pin connection (top view)
REG_DATA
BU/THERM
UART/SPI
2.2 Pin description
CD_PD
GND
RxD
RxTx
TxD
CLR/T
V
DD
MCLK
RSTO
WD
PA_IN-
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
TEST2
TEST1
VDC
RX_IN
CL
Vsense
X2
X1_OSCIN
SS
SV
TX_OUT
PA_IN+
CC
V
V
SS
PA_OUT
Table 1. Pin description
N° Name Type Description
Carrier, preamble or frame header detect output.
1 CD_PD Digital/Output
2R E G _ D A T A
3 GND Supply Digital ground
4 RxD Digital/Output RX data output.
5 RxTx
6T x D
Digital/Input
with internal pull-down
Digital/Input
with internal pull-up
Digital/Input
with internal pull-down
"1" No carrier, preamble or frame header detected
"0" Carrier, preamble or frame header detected
Mains or control register access selector
"1" - Control register access
"0" - Mains access
Rx or Tx mode selection input.
"1" - RX Session
"0" - TX Session
TX data input.
5/44
Pin settings ST7540
Table 1. Pin description (continued)
N° Name Type Description
Band in use/Thermal Shutdown event detection output.
In Rx mode:
"1" Signal within the programmed band
7 BU/THERM Digital/Output
8 CLR/T Digital/Output
9
V
DD
Supply/Power Digital supply voltage or 3.3V voltage regulator output
10 MCLK Digital/Output Master clock output
11 RSTO Digital/Output Power ON or watchdog reset output
"0" No signal within the programmed band
In Tx mode:
"1" - Thermal Shutdown event occurred
"0" - No Thermal Shutdown event occurred
(signal not latched)
Synchronous mains access clock or
control register access clock
Interface type:
“0” - Serial peripheral interface
“1” - UART interface
Watchdog input. The internal watchdog counter is
cleared on the falling edges.
12 UART/SPI
13 WD
Digital/Input
with internal pull-down
Digital/Input
with internal pull-up
14 PA_IN- Analog/Input Power line amplifier inverting input
15 PA_OUT Power/Output Power line amplifier output
16
17
V
SS
V
CC
Supply Power analog ground
Supply Power supply voltage
18 PA_IN+ Analog/Input Power line amplifier not inverting input
19 TX_OUT Analog/Output Small signal analog transmit output
20
SV
SS
Supply Analog signal ground
21 X1 Analog/Output Crystal oscillator output
22 X2 Analog/Input Crystal oscillator input - or external clock input
SENSE
(1)
Analog/Input Output voltage sensing input for the voltage control loop
23
V
Current limiting feedback.
24
CL
(2)
Analog/Input
A resistor between CL and SVSS sets the PLI current
limiting value. An integrated 80pF filtering input
capacitance is present on this pin.
25 RX_IN Analog/Input Receiving analog input
26 VDC Power 5V voltage regulator output
27 TEST1
Digital/Input
with internal pull-down
28 TEST2 Analog/Input
1. Cannot be left floating
2. Cannot be left floating
6/44
Test input. Must be connected to GND.
Test input. Must be connected SV
SS
ST7540 Electrical data
3 Electrical data
3.1 Maximum ratings
Table 2. Absolute maximum ratings
Symbol Parameter Value Unit
V
CC
V
DD
SVSS/GND Voltage between SVSS and GND
Power supply voltage -0.3 to + 14 V
Digital supply voltage -0.3 to +5.5 V
-0.3 to +0.3 V
V
I
V
O
I
O
,
V
sense
X2,PA_IN-
,PA_IN+, CL
Digital input voltage
Digital output voltage
GND - 0.3 to V
GND - 0.3 to V
Digital output current -2 to +2 mA
Voltage range at Vsense, X2, PA_IN-, PA_IN+, CL
Inputs
SVSS - 0.3 to 5.6
DD
DD
+0.3
+0.3
RX_IN Voltage range at RX_IN input -5.6 to 5.6 V
TX_OUT, X1 Voltage range at TX_OUT, X1 outputs
PA_OUT Voltage range at powered PA_OUT Output
I(PA_OUT)
T
A
T
STG
RxD,
PA _ OU T Pi n
Power line driver output current
Operating ambient temperature -40 to +85 °C
Storage temperature -50 to 150 °C
Maximum withstanding voltage range
Test condition: CDF-AEC-Q100-002- “Human
(1)
SVSS - 0.3 to 5.6
V
- 0.3 to +V CC +0.3
SS
650 mArms
±1750 V
Body Model”
Other pins ±2000 V
1. This current is intended as not repetitive pulse current
Acceptance criteria: “Normal Performance”
V
V
V
V
V
3.2 Thermal data
Table 3. Thermal data
Symbol Parameter
R
thJA1
R
thJA2
1. Mounted on Multilayer PCB with a dissipating surface on the bottom side of the PCB
2. It is the same condition of the point above, without any heatsinking surface on the board.
Maximum thermal resistance junction-ambient steady
(1)
state
Maximum thermal resistance junction-ambient Steady
(2)
State
HTSSOP28
Exposed Pad
Unit
35 ° C/W
70 ° C/W
7/44
Electrical data ST7540
3.3 Recommended operating conditions
Table 4. Recommended operating conditions
Symbol Parameter Test Condition Value Unit
V
CC
I(VCC)
- V
V
CC
DD
V
PA _O U T
I(PA_OUT)
Max allowed slope during
Power-up
Powered analog supply
Current with digital supply
provided externally
Maximum voltage
Difference between V
CC
and VDD during power-up
sequence
Output voltage swing for
PA_OUT pin
Maximum output
transmitting current in
programmable current
limiting
100 V/ms
Maximum total current 650 mArms
< 4.75V with 5V
V
DD
Digital supply provided
1.2 V
externally
-4.5 V
V
= 1.4kΩ; R
R
cl
LOAD
(as in Figure 17 )
=1Ω
CC
500 mArms
PP
8/44
ST7540 Electrical characteristics
4 Electrical characteristics
Table 5. Electrical characteristics
(
VDD = +5V,
unless otherwise specified)
Symbol Parameter Test condition Min. Typ. Max. Unit
V
DD
VCC =+9 V,
V
SS
Digital supply voltages
= S
VSS = GND = 0V,-40°C ≤ TA ≤ 85°C, TJ < 125°C,
5V Digital supply
provided externally
4.75 5 5.25 V
I(V
V
CC
DD
Power supply voltage 7.5 13.5 V
Digital input supply
)
current
Power supply current
I(V
CC
current with digital
)
supply provided
externally
UVLO
UVLO
HYS
Under voltage lock out
Threshold on V
UVLO Hysteresis on
V
CC
Digital I/O
R
down
R
up
Internal pull down
resistor
Internal pull up resistor -30% 100 +30% kΩ
Digital I/O - 5V digital supply
CC
Transmission &
receiving mode
(MCLK = 4MHz),no load
Transmission &
Receiving mode
(MCLK = OFF), no load
TX mode, no load 60 mArms
RX mode 5 mArms
3.7 3.9 4.1 V
340 mV
-30% 100 +30% kΩ
3.5 mA
1.5 mA
V
IH
V
IL
V
OH
V
OL
High logic level input
voltage
Low logic level input
voltage
High logic level output
voltage
Low logic level output
voltage
Digital I/O - 3.3V digital supply
V
IH
V
IL
High logic level input
voltage
Low logic level input
voltage
2 V
1.2 V
-
V
I
I
OH
OL
= -2mA
= 2mA
DD
0.45
GND
+ 0.3
V
V
1.4 V
0.8 V
9/44
Electrical characteristics ST7540
Table 5. Electrical characteristics (continued)
(
VDD = +5V,
VCC =+9 V,
V
= S
VSS = GND = 0V,-40°C ≤ TA ≤ 85°C, TJ < 125°C,
SS
unless otherwise specified)
Symbol Parameter Test condition Min. Typ. Max. Unit
V
V
OH
V
OL
Oscillator
High logic level output
voltage
Low logic level output
voltage
IOH= -2mA
= 2mA
I
OL
DD
0.75
-
GND
+ 0.4
V
V
External Clock X2 voltage swing External clock. Figure 4 5
External Clock
X2 DC voltage level External clock. Figure 4 2.5 V
DC XTAL Clock duty cycle External clock. 40 60 %
Xtal
Xtal
ESR
Crystal oscillator
frequency
External oscillator esr
resistance
fundamental 16 MHz
External oscillator
Xtal
CL
stabilization
Figure 6 16 pF
capacitance
Transmitter
I
TX_OUT
V
TX_OUT
V
TX_OUTDC
HD2
TX_OUT
HD3
TX_OUT
G accuracy
Output transmitting
current on TX_OUT
Max carrier output AC
voltage
Output DC voltage on
TX_OUT
Second harmonic
distortion on TX_OUT
Third harmonic
distortion on TX_OUT
Accuracy on voltage
control loop active
= 1.4kΩ
R
CL
Vsense = 0V
TX_OUT
= 2VPP;
V
Fc = 86KHz, no load
TX_OUT
= 2VPP;
V
Fc = 86KHz, no load
= 0Ω
R
CL
1.75 2.3 3.5
1.7 2.1 2.5 V
-1 +1 GST
V
pp
40 Ω
1m A r m s
V
PP
-42
-49
dB
dB
c
c
G
ST
ALC gain step control
loop gain step
DRNG ALC dynamic range 30 dB
C
CL
Input capacitance on
CL pin
Voltage control loop
V
senseTH
reference threshold on
pin
V
sense
Figure 17 160 180 200
Hysteresis on voltage
V
senseHYST
loop reference
Figure 17 ±18 mV
threshold
10/44
0.6 1 1.4 dB
80 pF
mV
PK
ST7540 Electrical characteristics
Table 5. Electrical characteristics (continued)
(
VDD = +5V,
VCC =+9 V,
V
= S
VSS = GND = 0V,-40°C ≤ TA ≤ 85°C, TJ < 125°C,
SS
unless otherwise specified)
Symbol Parameter Test condition Min. Typ. Max. Unit
V
SENSE
CL
CL
T
RxTx
T
T
TH
HYST
ALC
ST
V
SENSE
Input
impedance
Current control loop
reference threshold on
CL pin
Hysteresis on current
loop reference
threshold
Carrier activation time
Carrier stabilization
time
from STEP 16 to zero
or from step 16 to step
31,
Tstep
36 kΩ
Figure 17 1.80 1.90 2.00 V
Figure 17 210 250 290 mV
Figure 21 - 600
Baud Xtal = 16MHz
Figure 21- 1200 Baud
Xtal = 16MHz
Figure 21- 2400 Baud
Xtal = 16MHz
Figure 21- 4800 Baud
Xtal = 16MHz
Figure 21
Xtal = 16MHz
Figure 21
Xtal = 16MHz
1.6 ms
800 µs
400 µs
200 µs
3.2 ms
200 µs
Power amplifier
PA
IN(Offset)
GBWP
R
IN
C
IN
CMRR
Input terminals
OFFSET
Gain bandwidth
product
Input resistance at
PA_IN+ and PA_INpins
Input capacitance at
PA_IN+ and PA_INpins
Common mode
rejection ratio
±18 mV
100 MHz
PA_IN+ vs. Vss
PA_IN- vs. Vss
PA_IN+ vs. Vss
PA_IN- vs. Vss
(1)
(1)
(1)
(1)
1 M Ω
1 M Ω
5p F
5p F
40 dB
11/44
Electrical characteristics ST7540
Table 5. Electrical characteristics (continued)
(
VDD = +5V,
VCC =+9 V,
V
= S
VSS = GND = 0V,-40°C ≤ TA ≤ 85°C, TJ < 125°C,
SS
unless otherwise specified)
Symbol Parameter Test condition Min. Typ. Max. Unit
HD2
HD3
Receiver
V
V
R
PA_ O U T
PA_ O U T
IN
IN
IN
Second harmonic
distortion on PA_OUT
V
V
R
Carrier frequency:
PA _O U T
= 12V
CC
LOAD
= 5.6V
= 30Ω
PP
,
-63
dB
86KHz
Figure 3
Third harmonic
distortion on PA_OUT
pin
PA _O U T
= 12V
CC
LOAD
= 5.6V
= 30Ω
V
V
R
Carrier frequency:
86KHz
PP
,
- 63
dB
Figure 3
Input sensitivity
(Normal Mode)
Input sensitivity
(High Sens.)
Input sensitivity (TxD
line forced to “1”)
0.5 2
250
V
BU
Maximum input signal 2
mV
µ V
dB/
µVrms
V
rms
Input impedance 80 100 140 kΩ
Carrier detection
sensitivity
0.5 2
mV
(Normal Mode)
c
c
rms
rms
rms
Carrier detection
V
CD
sensitivity
(High Sensitivity Mode)
Carrier detection
sensitivity
(TxD forced to “1”)
V
BU
Band in Use Detection
Level
12/44
250
V
BU
83.5 86
µ V
rms
dB/
µVrms
dB/
µVrms
ST7540 Electrical characteristics
Table 5. Electrical characteristics (continued)
(
VDD = +5V,
VCC =+9 V,
V
= S
VSS = GND = 0V,-40°C ≤ TA ≤ 85°C, TJ < 125°C,
SS
unless otherwise specified)
Symbol Parameter Test condition Min. Typ. Max. Unit
5V Voltage regulator
VDC
Linear regulator output
voltage
3.3V Voltage regulator
V
DD
Linear regulator output
voltage
Other functions
T
RSTO
T
T
T
T
T
T
OFFD
T
T
M
WD
WM
WO
OUT
OFF
CD
DCD
CLK
Reset time
Watch-dog pulse width See Figure 23 125 ns
Watch-dog pulse
period
Watch-dog time out See Figure 23 1.5 s
TX time out
Time Out OFF time Figure 22 125 ms
RxTx 0->1 vs. time out
delay
Carrier detection time
selectable by register
CD_PD Propagation
delay
Master clock output
selectable by register
0 < Io < 50mA
7.5V < V
CC
< 13.5V
0 < Io < 50mA
7.5V < V
CC
< 13.5V
See Figure 23 ;
Xtal = 16MHz
Minimum value.
See Figure 23
Maximum value.
See Figure 23
Control register bit 7
and bit 8
-5% 5.05 +5% V
-5% 3.3 +5% V
50 ms
250 ns
1490 ms
1
3
Figure 22 20 µs
Control register
bit 9 and bit10
Figure 14
500
1
3
5
µ s
ms
ms
ms
Figure 14 300 500 µs
Control register
bit 15 and bit 16
See Ta bl e 1 2
fclock
fclock/2
fclock/4
off
MHz
s
BAUD Baud rate
Control register
bit 3 and bit 4
See Ta bl e 1 2
600
1200
2400
4800
Baud
13/44
Electrical characteristics ST7540
Table 5. Electrical characteristics (continued)
(
VDD = +5V,
VCC =+9 V,
V
= S
VSS = GND = 0V,-40°C ≤ TA ≤ 85°C, TJ < 125°C,
SS
unless otherwise specified)
Symbol Parameter Test condition Min. Typ. Max. Unit
Serial Interface
1667
T
B
Baud rate Bit Time
(1/BAUD)
Control register bit 3
and bit 4
(See Figure 13 )
833
417
208
µ s
Ts Setup time
T
H
T
CR
T
CC
T
DS
T
DH
T
CRP
1. Not tested, guaranteed by design
Hold time
CLR/T vs. REG_DATA
or RxTx
CLR/T vs. CLR/T
Setup time
Hold time
see Figures 8, 9, 10, 11
& 12
see Figures 8, 9, 10, 11
& 12
see Figures 8, 9, 10, 11
& 12
see Figures 8, 9, 10, 11
& 12
see Figures 8, 9, 10, 11
& 12
see Figures 8, 9, 10, 11
& 12
T
B
/4 TB/2
T
B
/4 TB/2
T
B
T
H
Figure 3. PLI configuration for PA_OUT distortions measurement
150 pF 100 pF
5 k
2.7 kΩ
Ω
5n s
2n s
/4
T
B
2*T
B
TB/2
PA_IN -
PA
V
AC
V
DC
10 kΩ
= 2Vpp
= 1.9 V
PA_IN +
14/44
Vcc
Vss
PA_OUT
1uF
30 Ω
D03IN142
Measurement point