资源描述
STX210A
OOK/ASK/Transmitter
Description
STX210A is one OOK/ASK transmitter with integrated transmitting data encoder. The circuit working frequency range is about 200MHz-500MHz. The encoder has single external input enable pin. The transmitted bit pattern is consistent with XX1527 encoder.
STX210A integrates most transmitter components on-chip and only requires a few external components to work as a transmitter. The STX210A has transmission data encoder, low supply detection, and long-time mis-transmission shutdown protection features.
Features
Working frequency range: 200MHz-500MHz.
• Tunable output power: 15dBm @ 5V with 50 ohm load, typ.
• Transmitted data pattern consistent with XX1527 encoder.
• Wide supply voltage: 2.3V-5.5V for 315/433MHz.
• Low supply voltage detection
• Automatic shutdown protection
Applications
• Wireless Door-bell.
• Remote Control, Garage door and gate openers
• AMR-Automatic Meter Reading
• Wireless alarm and security system.
Block Diagram
锐迪芯电子
STX210A
OOK/ASK/Transmitter
Pin Configuration
Table 1. Pin Description
Pin
Symbol
I/O
Description
1
VSSA
IO
RF Gound
2
POUT
O
Transmitted RF output, can stand 20V DC voltage.
3
VDCC
LDO Power for dig part, connected ext bypass cap.
4
RATE
IO
Ext connected res, Control TX data rate
5
D1
I
Transmit input control, active high, default low
6
VACC
IO
LDO Power for RF part, connected ext bypass cap.
7
VDDA
IO
Vdd for whol chip
8
XI
I
Input terminal of local oscillation signal. It is connected to
the crystal or driven by an external clock.
Table 2. Absolute Maximum Rating
Item
Rating
Supply Voltage, VDD
+ 5.6V
Inputs and Clock Outputs
- 0.5V to + 5.6V
Pout pin
-0.5V to +20V
Storage Temperature
- 65 to + 150 oC
Soldering Temperature
+ 260 oC
STX210A
OOK/ASK/Transmitter
Table 3. Electrical Specifications
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
Supply
V
2.2
5.5
V
Voltage
200MHz-500MHz
DD
Supply
I
Fout=434MHz, 13dBm , 3V
15
mA
Current
DD
Fout=434MHz, 18dBm , 5V
25
mA
RF Power
Pratio
200MHz-500MHz
dB
On/Off Ratio
60
Pout supply
Pvol
200MHz-500MHz
12
V
voltage
Transmitted
Pout
Fin=315MHz , Vdd=5V
20
dBm
Power
Fin=434MHz , Vdd=5V
20
dBm
Data Rate
OOK/ASK mode
0.5
20
Kb/s
OSCI
operating
F
9
10
20
MHz
Frequency
OSC
Operating
T
-40
27
85
℃
Temperature
a
Leakage
I
Power down mode
1
uA
Current
SB
Typical Application Circuit I —315/433MHz Transmitter
STX210A
OOK/ASK/Transmitter
Functional Description
Crystal Oscillator
The crystal oscillator circuit consists of a colpit oscillator. Pin 8 can drive one off-chip 9MHz-30MHz crystal without external capacitors required. The driving capacitors are integrated on Chip.
The crystal driver stage can also take input clock as input clock buffer. The crystal oscillator frequency is determined as follows
fosc= fvco / 32
Where Fvco is VCO oscillation frequency. 32 is PLL divider value. Below table lists the required Crystal frequency. The suggested crystal ESR must be less than 50Ω.
Transmitting Frequency
Crystal Frequency
Note
(MHz)
(MHz)
315
9.844
340
10.625
390
12.188
433.92
13.56
PLL Block
The PLL consists of phase-frequency detector (PFD), charge pump, loop filter, voltage-controlled oscillator (VCO), and divider (32). The PFD compares two signals and produces an error signal which is proportional to the two signal phase difference. The error signal is used to control the VCO to run fast or slow.
The VCO oscillation frequency range is tunable between200MHz-500MHz.
OOK/ASK Modulation
The OOK/ASK modulation is done by external Pin D1. D1 turn on/off the power amplifier when D1 is high or low. The PLL loop is on no matter DIN is high and low. However, to save power, the whole chip is turned off after D1 stay in low over one million crystal oscillation cycles. That is about 100ms for 10MHz crystal. When D1 is high, the whole chip is powered up. The On/Off power ratio is larger than 60dB.
STX210A
OOK/ASK/Transmitter
TX RATE CONTROL
The transmitting rate is controllable with external control pin RATE connected with different resistor. Below table lists the transmitting rate with different ext resistor. The bit rate changes less with supply voltage.
Table x The transmitting time vs external resistor when pins D1 is hold at high.
Ext Resistor
Vcc=2.5V ,
Vcc=2.5V ,
note
(K.Ω)
1T Bit width
Bit Rate
(ms),
(kb/s)
220
0.12
8.0
330
0.16
6.0
470
0.25
4.0
690
0.34
3.0
1000
0.50
2.0
Fig. 1 Transmitting bit rate vs Supply voltage and ext bias resistor.
STX210A
OOK/ASK/Transmitter
RF OUTPUT
The ANT pin can be matched to 50 Ohm with a Π-type circuit. The supply voltage can be as high as 12V. Below table is suggested inductor and capacitor value for different frequency.
Frequency
L1
L2
C1
C2
C3
C4
R1
Note
(MHz)
(nH)
(nH)
(uF)
(pF)
(pF)
(pF)
(Ω)
315
470
100
1.0
NC
NC
10
100
433
470
82
1.0
NC
NC
5
100
ENCODER
The chip integrates the control data encoder. The transmitted data pattern is encoded within the internal OTP encoder. The data pattern is consistent with market available product XX1527.
STX210A
OOK/ASK/Transmitter
Package Information SOP-8
展开阅读全文