SA818S : 1W Embedded Analog Walkie Talkie Module With AMP & LNA

SA818S is a cost-effective integrated professional walkie-talkie module, built-in high-speed microcontroller, high-performance RF transceiver chip and RF power amplifier, and provides a standard serial port to communicate with the module, so that the relevant parameters of the module and the transceiver can be set quickly and easily. Function to control. Users only need to connect an audio amplifier, microphone, and speaker to this module to work as a small walkie-talkie. The simplified interface and ultra-small size enable this module to be widely used, and it can also be easily and quickly embedded in various handheld devices to improve the overall performance of the terminal product. SA818S strictly uses lead-free technology for production and testing, and meets RoHS and Reach standards.
The SA818S walkie-talkie module adds an LNA circuit on the basis of SA818, and the sensitivity is increased by 4dBm. For the entire frequency range of 400-470MHz, the power output fluctuation is less than 1dB, and the low power can achieve an error of 27dBm+/-1dBm from 400-470MHz. Note: The software and hardware interfaces are the same as before and are compatible with each other.
The SA818S is strictly manufactured and tested using lead-free processes, complying with RoHS and Reach standards. The SA818S module is also available in a version that meets CE certification to cater to different market demands.

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Parameter	Test condition	Min	Typ.	Max	Unit
Power supply		3.3	4.2	5.5	V
Working Temperature range		-30	25	70	℃
Current Consumption
Sleep current			≤1		uA
RX current			60		mA
TX current（High power）			650	750	mA
TX current（low power）			450	550	mA
Transmitting RF Parameters
Frequency range	UHF	400		480	MHz
Frequency range	VHF	134		174	MHz
Out power（high power）	@VCC=4.0V	28	29.5	31	dBm
Out power（low power）	@VCC=4.0V	25	26.5	27	dBm
Modulation frequency	@1.5KHz/2.5KHz frequency deviation		10		mV
Audio modulation distortion	@1.5KHz/2.5KHz frequency deviation		2	5	%
SignaltoNoiseRatio	@1.5KHz/2.5KHz frequency deviation	38	40	45	dB
adjacent-channel power	@12.5K offset		-60		dBc
CTCSS Modulation frequency		0.35	0.5	0.75	KHz
Receiving RF Parameters
Receiving sensitivity			-124		dBm
Receiving SNR	@1.5KHz frequency deviation	45	50		dB
Audio output amplitude			700		mV
Audio Output impedance			200		OHm

Type	Analog walkie talkie
Output Power	500mW,1W

Features of Walkie Talkie Module SA818S

UHF band frequency: 400~480 MHz
VHF band frequency: 134~174 MHz
(Above 3 frequency bands are optional，
also below 2 frequency bands can be
designed specially)
Tx and Rx frequency, Tx and Rx CTCSS, CDCSS can be set alone.
Band width: 12.5 KHz / 25 KHz
Output power up to 1W
Distance up to 4-5km in open area
Sensitivity：-124 dBm
High-integrated, Small Size
38 CTCSS
166 CDCSS
8 level squelch
8 adjustable volume
High/ low power is optional（500mW/1W）
Wide range of working voltage: 3-5.5 V
0.5 ppm KDS TCXO crystal, Stable performance

Application circuit of wireless module SA818S.

Pin definition of wireless module SA818S

Pin NO.	Pin name	I/O state
1	Audio ON	Connected to audio power amplifier. When the module worked, it can control the extra audio amplifier automatically, it will output low level to turn on the amplifier and high level to turn off the amplifier.
2	NC	Not connected
3	AF_OUT	Audio output
4	NC	Not connected
5	PTT	Module Input, Transmitting/receiving control, "0" force the module to enter TX state; and "1" to Rx state
6	PD	Power Down control, "0" for power down mode; "1" for the normal work
7	H/L	high/low output power control; Leave open for high output power，low level to low output power. (Please kindly note: this pin can NOT be connected to VDD or high level of cmos output)
8	VBAT	Connect power positive
9	GND	Grounding
10	GND	Grounding
11	NC	Not connected
12	ANT	connect 50 ohm antenna
13,14,15	NC	Not connected
16	RXD	RXD of the module and connect to external TXD *Before enter sleep mode, user need to pull low RXD Pin to prevent current leakage or poor reset in the next time.
17	TXD	TXD of the module and connect to external RXD
18	MIC_IN	Microphone or line in

Mechanical dimensions of wireless module SA818S.