CMT2157A-ESR from HopeRF Micro-electronics, in a SOIC-14. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	LED	output	LED driver output, active low, which lights or flashes to indicate transmission and low battery detection, with drive current limited by the LED driving capability.
2	VDD	power_in	Power supply input; the recommended operating supply range is 1.8 to 3.6 V.
3	GND	power_in	Ground reference for the device.
4	RFO	output	Power amplifier output, with output power specified from -10 to +13 dBm.
5	K7	input	Push button 7 input for the encoder; the device supports up to 7 configurable push-button data pins.
6	K6	input	Push button 6 input for the encoder; the device supports up to 7 configurable push-button data pins.
7	K5	input	Push button 5 input for the encoder; the device supports up to 7 configurable push-button data pins.
8	K4	input	Push button 4 input for the encoder; the device supports up to 7 configurable push-button data pins.
9	K3	input	Push button 3 input for the encoder; the device supports up to 7 configurable push-button data pins.
10	K2	input	Push button 2 input for the encoder; the device supports up to 7 configurable push-button data pins.
11	K1	input	Push button 1 input for the encoder; the device supports up to 7 configurable push-button data pins.
12	DATA	bidirectional	Data pin to access the embedded EEPROM, internally pulled up to VDD.
13	CLK	input	Clock pin to access the embedded EEPROM, internally pulled up to VDD.
14	XTAL	input	26 MHz single-ended crystal oscillator input or external 26 MHz reference clock input, which requires a coupling capacitor and 0.3 to 0.7 Vpp amplitude when driven externally.

Key specifications

Parameter	Value
Manufacturer	HopeRF Micro-electronics
Package	SOIC-14
Category	RF & Radio
Pins	14

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter	Symbol	Min	Typ	Max	Unit	Conditions	Page
Operation Voltage Supply	VDD	1.8		3.6	V		5
Operation Temperature	TOP	-40		85	℃		5
Supply Voltage	VDD	-0.3		3.6	V		5
Interface Voltage	VIN	-0.3			V		5
Junction Temperature	TJ	-40		125	℃		5
Storage Temperature	TSTG	-50		150	℃		5
ESD Rating Human Body Model (HBM)		-2		2	kV		5
Latch-up Current		-100		100	mA	@ 85 ℃	5
Frequency Range	FRF	240		960	MHz		6
Symbol Rate FSK/GFSK	SR	0.5		100	ksps		6
Symbol Rate OOK	SR	0.5		40	ksps		6
(G)FSK Modulation Deviation Range	FDEV	1		200	kHz		6
Maximum Output Power	POUT(Max)			13	dBm		6
Minimum Output Power	POUT(Min)	-10			dBm		6
PA Ramping Time	tRAMP	0		1024	us		6
Sleep Current	ISLEEP			20	nA		1
Crystal Frequency	FXTAL	26	26	26	MHz		7
Crystal Tolerance		-20		20	ppm		7
Load Capacitance	CLOAD	12		20	pF		7

CAD (KiCad official)

Symbol: CMT2157A-ESR
Footprint: Package_SO:SOIC-14_3.9x8.7mm_P1.27mm
3D model: SOIC-14 (KiCad packages3D, STEP)
3D model files: cmt2157a-esr-etched.step / cmt2157a-esr-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); cmt2157a-esr.step / cmt2157a-esr.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: HopeRF Micro-electronics datasheet (31 pp, sha256 687441d9010dcd89, retrieved 2026-11-05, tier: lcsc)
Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-5-5 (text), consensus claude-sonnet-5-5 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF

CMT2157A-ESR

Verified CMT2157A-ESR

Verification log 1 record

3D Model

Symbol & Footprint

Schematic Symbol

PCB Footprint

Datasheet

README