DMR818S-U : FCC ID & CE RED Certified DMR Tier II AMBE++ Walkie Talkie Module

DMR818S is a 2W TIER II & long distance DMR walkie talkie module, it comes with built-in high performance microcontroller, digital mobile radio IC and RF power amplifier. All parameters(CTCSS, CDCSS, SQ, Predefined channels etc.) can be easily modified with protocol. With external power supply, speaker, and audio amplifier, it is easy to become a professional digital walkie talkie. Simplified interface and Ultra small size make this module widely used in various applications and conveniently embedded into various handheld device.
Remark: there are two versions of this module: DMR818S-NVOC & DMR818S-AMBE.
DMR818S strictly uses lead-free process for production and testing, and meets RoHS and REACH standards.
DMR818S-U has obtained CE-RED and FCC ID certification.

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Parameters	Test condition	Min.		Typ.		Max		Unit
Voltage range		3.3		4.2		4.5		V
Operating Temperature		-20		25		60		℃
Frequency range	@UHF	400				470		MHz
	@VHF	134				174		MHz
	@350	320				400		MHz
Start time				2000				ms
Uart baud rate				57600				bps
Current Consumption
Sleep current	CS pulled low for 3 seconds			< 55				uA
Rx current				<135				mA
Tx current （high power）	@VCC=4.2V, 2w analog			<1300				mA
	@VCC=4.2V, 2w digital			<1000				mA
Tx current （low power）	@VCC=4.2V, 0.5w analog			<650				mA
	@VCC=4.2V, 0.5w digital			<500				mA
RF Parameters
Tolerance of frequency				1		1.5		ppm
Modulation sensitivity	1.5KHz/2.5KHz frequency offset (N/W)	6		7		12		mv
Adjacent-channel power	@12.5K offset	-60		-62				dBm
Mic input voltage				0.1		1.6		Vpp
CTCSS modulation frequency offset		0.35		0.4		0.6		KHz
Modulation characteristics	300Hz	-13		-11		-9		dB
	500Hz	-9		-6		-5		dB
	1000Hz	-3		0		1		dB
	2000Hz	3		6		7		dB
	3000Hz	5		7		11		dB
Rx Parameters
Sensitivity	Analog (12db SNR)		-120				dBm
Receiving BER(DMR modulation)	@ -118dBm		5				%
Audio output amplitude					500		mV
Audio Output impedance			30				KOhm
Adjacent channel selectivity	Offset:+12.5KHz	60					dB
	Offset:+12.5KHz

Features of DMR Walkie Talkie Module DMR818S

UHF band frequency: 400~470 MHz
VHF band frequency: 134~174 MHz
350 band frequency: 320~400 MHz
Distance up to 5Km
Max power output to 2W, low power to 0.5W
High Sensitivity: -124dBm
Bit error rate down to 1% under -121dBm
Independent frequency for Tx and Rx.
9 adjustable volume
Analog Bandwidth: 12.5 / 25 KHz Digital Bandwidth:6.25KHz
Message transmission and reception
DMR(Digital Mobile Radio)/ Analog walkie talkie
Built-in EEPROM, data saved even powered off
1ppm TCXO crystal
51 CTCSS
166 CDCSS

Typical application circuit

Pins of DMR Walkie Talkie Module DMR818S

PIN DEFINITION

Pin NO.	Pin name	I/O	Level standard	Description
1	MIC_IN	I		Microphone or line in
2	UART-TX	O	0-3.3V	UART-TXD
3	UART-RX	I	0-3.3V	UART-RXD
4, 12	NC
5	HST_TXD	O	0-3.3V	Transmit data pin (for upgrading program)
6	HST_RXD	I	0-3.3V	Receive data pin (for upgrading program)
7	ANT			connect 50 ohm antenna
8, 9, 10	GND	-		Ground
11	VCC	-	0-5V	External and Positive supply 3.3~5V
13	CS	I	0-5V	High level for normal working, leave open or pull low to enter sleeping mode
14	PTT	I	0-3.3V	Module Input, Transmitting/receiving control, pull low to force the module to enter TX state; pull high for Rx state
15	+3.3V	-		3.3V output, connect to 50mA
16	LINE_OUT	O		Audio output
17	T/R	O	0-3.3V	Module Output, status of Transmitting/receiving, High for TX and low for Rx
18	SPKEN	O	0-3.3V	Audio amplifier control
19, 20	GND	-		Ground

MECHANICAL DIMENSIONS

Mechanical Dimensions of DMR Walkie Talkie Module DMR818S