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CMT2157AW 

 

 

 

Rev 0.8 | Page 1/31 

 

www.hoperf.com 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CMT2157AW 

240 – 960 MHz (G)FSK/OOK Stand-Alone Transmitter with Encoder

 

Copyright © By CMOSTEK   

 

Features

 

 

Embedded EEPROM 

  Very Easy Development with RFPDK   

  All Features Programmable 

 

Frequency Range: 240 to 960 MHz 

 

FSK, GFSK and OOK Modulation 

 

Symbol Rate:   

  0.5 to 100 ksps (FSK/GFSK) 

  0.5 to 40 ksps (OOK) 

 

Deviation: 1.0 to 200 kHz 

 

Output Power:

 

-10 to +13 dBm   

 

Sleep Current: < 20 nA 

 

Stand-Alone, No External MCU Control Required 

 

Embedded 1920, 1527 and 2262 Data Encoder 

 

Up to 7 Configurable Data Pins for Push Buttons 

 

LED Indicator for Low Battery Detection and Transmission 

 

Sync ID Auto-Study with CMOSTEK Receiver 

 

FCC / ETSI Compliant 

 

RoHS Compliant 

 

14-pin SOP Package 

 

Applications 

 

Low-Cost Consumer Electronics Applications 

 

Home and Building Automation 

 

Remote Fan Controllers 

 

Infrared Transmitter Replacements 

 

Industrial Monitoring and Controls 

 

Remote Lighting Control 

 

Wireless Alarm and Security Systems 

 

Remote Keyless Entry (RKE) 

 

 

 

Descriptions 

The CMT2157AW is a true single-chip, highly flexible, high 

performance, (G)FSK/OOK RF transmitter with embedded 

data encoder ideally  for 240 to 960 MHz wireless 

applications. The device integrates a data encoder that is 

not only compatible with the most common used encoding 

format of 1527 and 2262, but also a more efficient, flexible 

and powerful format of 1920 designed by CMOSTEK.  Up 

to  7  configurable  push buttons are supported in multiple 

button modes. When pairing the device to  CMOSTEK 

receiver, the  synchronization ID can be programmed into 

both of the transmitter and receiver during the 

manufacturing phase, or studied by the receiver from the 

transmitter remotely by end customers. An embedded 

EEPROM allows the RF and encoder parameters to be 

programmed into the chip using the CMOSTEK USB 

Programmer and the  RFPDK. Alternatively, in stock 

product of 868.35 MHz is available for immediate demands 

without the need  of EEPROM programming. The 

CMT2157AW  is part of the CMOSTEK NextGenRF

TM

 

family, together with CMT225x series  receivers, they 

enable ultra low cost, low power consumption RF links. 

Ordering Information 

Part Number 

Frequency 

Package 

MOQ 

CMT2157AW-ESR 

868.35 MHz 

T&R 

2,500 pcs 

CMT2157AW-ESB 

868.35 MHz 

Tube 

1,000 pcs 

More Ordering Info: See 

Page 26

 

 

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14

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10

9

8

11

LED

VDD

GND

RFO

K7

K6

K5

XTAL

CLK

DATA

K1

K2

K3

K4

 

CMT2157AW 

 

SOP14 

 

Summary of Contents for CMT2157AW

Page 1: ...ith embedded data encoder ideally for 240 to 960 MHz wireless applications The device integrates a data encoder that is not only compatible with the most common used encoding format of 1527 and 2262 b...

Page 2: ...chematic Table 1 BOM of 433 92 868 35 MHz Typical Application Designator Descriptions Value Unit Manufacturer 433 92 MHz 868 35 MHz U1 CMT2157AW 240 960 MHz G FSK OOK stand alone transmitter with enco...

Page 3: ...Loop PN Phase Noise ESD Electro Static Discharge RBW Resolution Bandwidth ESR Equivalent Series Resistance RCLK Reference Clock FSK Frequency Shift Keying RF Radio Frequency GFSK Gauss Frequency Shift...

Page 4: ...view 12 5 2 Modulation Frequency Deviation and Symbol Rate 12 5 3 Embedded EEPROM and RFPDK 13 5 4 Power Amplifier 15 5 5 PA Ramping 15 5 6 Working States 16 5 7 The Encoder 17 5 7 1 1920 Packet Struc...

Page 5: ...Conditions Min Max Unit Supply Voltage VDD 0 3 3 6 V Interface Voltage VIN 0 3 VDD 0 3 V Junction Temperature TJ 40 125 Storage Temperature TSTG 50 150 Soldering Temperature TSDR Lasts at least 30 sec...

Page 6: ...dBm 26 7 mA FSK 13 dBm 35 3 mA Sleep Current ISLEEP 20 nA Frequency Tune Time tTUNE 370 us Phase Noise 433 92 MHz PN433 92 100 kHz offset from FRF 80 dBc Hz 600 kHz offset from FRF 96 dBc Hz 1 2 MHz...

Page 7: ...e CMT2157AW can directly work with external 26 MHz reference clock input to XTAL pin a coupling capacitor is required with amplitude 0 3 to 0 7 Vpp 2 This is the total tolerance including 1 initial to...

Page 8: ...in Number Name I O Descriptions 1 LED O LED driver active low 2 VDD I Power supply input 3 GND I Ground 4 RFO O Power amplifier output 5 11 K 7 1 I Push button 7 to 1 12 DATA IO Data pin to access the...

Page 9: ...K Spectrum 50 40 30 20 10 0 10 20 433 62 433 72 433 82 433 92 434 02 434 12 434 22 Power dBm Frequency MHz FSK vs GFSK FSK GFSK 50 40 30 20 10 0 10 433 17 433 37 433 57 433 77 433 97 434 17 434 37 434...

Page 10: ...nductance between the ground pour and the GND pins Avoid using long and or thin transmission lines to connect the components Avoid placing the nearby inductors in the same orientation to reduce the co...

Page 11: ...long and or thin transmission lines to connect the components Avoid placing the nearby inductors in the same orientation to reduce the coupling between them Place C0 as close to the CMT2157AW as poss...

Page 12: ...OR to an internal reference voltage source The calibration can help the chip to finely work under different temperatures and supply voltages The transmission is triggered by pressing the push button s...

Page 13: ...n the RFPDK CMT2157AW Interface CMOSTEK USB Programmer CLK DATA RFPDK EEPROM Figure 12 Accessing Embedded EEPROM For more details of the CMOSTEK USB Programmer and the RFPDK please refer to AN113 CMT2...

Page 14: ...n 1920 mode 3 Basic Advanced Number of Packets This defines the minimum number of packet s being transmitted during each button pressing action It also defines the number of packet s being transmitted...

Page 15: ...ier PA is integrated in the CMT2157AW to transmit the modulated signal out Depending on the application the user can design a matching network for the PA to exhibit optimum efficiency at the desired o...

Page 16: ...o the SLEEP state When the device works in the periodic transmission mode the device periodically wakes up from the SLEEP state goes the same sequence performs the transmission and goes back to the SL...

Page 17: ...The following sections only give the abstracts of these formats In the below explanations some elements in the packet are measured in the unit of symbol while some of them are measured in the unit of...

Page 18: ...e unit of bit 2 SYM 2 SYM 1 SYM 1 SYM Bit 1 Bit 0 1 SYM 1 SYM 3 SYM 3 SYM Bit 1 Bit 0 3 SYM 2 SYM Bit 1 2 SYM 3 SYM Bit 0 2 SYM 1 SYM Bit 1 1 SYM 2 SYM 1 SYM 1 SYM Bit 0 1 SYM 3 SYM 3 Symbols Bit 4 Sy...

Page 19: ...4 D5 D6 field have the unit of bit 1 SYM 1 SYM 3 SYM 3 SYM Bit 1 Bit 0 Figure 19 1527 Bit Format Options 5 7 3 2262 Packet Structure ID Study is not supported in 2262 mode Only one packet structure is...

Page 20: ...packet formats In 1920 format it is from 1 to 32 bits In 1527 format it is fixed at 20 bits The ID Study is initialized by the CMT2157AW It is done by executing the following steps An example of CMT2...

Page 21: ...determined by the Sync ID Length The figure below gives an example which 4 push button keys are selected LED VDD GND RFO K7 K6 K5 XTAL CLK K0 K1 K2 K3 K4 D0 D1 D2 D3 NC NC NC NC LED VDD GND RFO CLK X...

Page 22: ...ser is able to use the 5 buttons K1 B0 K5 B4 to generate different combinations of the data D0 D3 to be transmitted The number of data bits to be transmitted is fixed at 4 The table below shows the ma...

Page 23: ...down again the D1 is set to 0 in the current transmission and so on This is what it means by Toggle See the table below for the examples of toggle button mode Table 18 Examples of the Toggle Button Mo...

Page 24: ...tify the user the battery is running out 5 11 Low Battery Detection LBD This defines the Low Battery Detection threshold Once the LBD is enabled the chip will automatically check the battery status be...

Page 25: ...MT2157AW by feeding the clock into the chip via the XTAL pin This further saves the system cost due to the removal of the crystal A coupling capacitor is required if the RCLK is used The recommended a...

Page 26: ...6 V 40 to 85 1 000 Note 1 E stands for extended industrial product grade which supports the temperature range from 40 to 85 S stands for the package type of SOP14 R stands for the tape and reel packag...

Page 27: ...E1 E Figure 29 14 Pin SOP Package Table 20 14 Pin SOP Package Dimensions Symbol Size millimeters Min Typ Max A 1 75 A1 0 05 0 225 A2 1 30 1 40 1 50 A3 0 60 0 65 0 70 b 0 39 0 48 C 0 21 0 26 D 8 45 8 6...

Page 28: ...57AW Top Marking Explanation Mark Method Laser Pin 1 Mark Circle s diameter 1 mm Font Size 0 35 mm right justified Line 1 Marking CMT2157A represents part number CMT2157AW Line 2 Marking YYWW is the D...

Page 29: ...etwork and other application layout design related issues AN142 CMT2157A Configuration Guideline Details of configuring CMT2157AW features on the RFPDK AN113 CMT2157A 2250 1 A One Way RF Link Developm...

Page 30: ...CMT2157AW Rev 0 8 Page 30 31 www hoperf com 10 Document Change List Table 23 Document Change List Rev No Chapter Description of Changes Date 0 8 All Initial released version 2015 02 11...

Page 31: ...ity is assumed for inaccuracies and specifications within this document are subject to change without notice The material contained herein is the exclusive property of CMOSTEK and shall not be distrib...

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