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Contents

README

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Si24R2H

Nanjing Zhongke Microelectronics · RF Transceiver ICs · QFN-32-EP(4x4)

Si24R2H from Nanjing Zhongke Microelectronics, in a QFN-32-EP(4x4). 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 NTC_VB output NTC bias-voltage analog output for the thermistor temperature-sensing circuit.
2 NTC_VB_N passive NTC bias-voltage analog pin, paired with NTC_VB.
3 XIN input Optional 32.768 kHz crystal oscillator input; when an external clock is applied to XOUT, XIN must be connected to VCC.
4 XOUT output Optional 32.768 kHz crystal oscillator output, which also serves as the direct input for an external 125 kHz-receiver clock.
5 DAT output Data output carrying the demodulated 125 kHz receiver signal.
6 GND power_in Ground (0 V).
7 VCC power_in Power supply, 2.4 V to 3.6 V (typical 3 V).
8 CL_DAT output Manchester-recovered clock output; DAT data is stable on the rising edge of CL_DAT.
9 LF3P input 125 kHz receiver channel 3 input.
10 LF2P input 125 kHz receiver channel 2 input.
11 LF1P input 125 kHz receiver channel 1 input.
12 LFN input Common ground for the 125 kHz receiver channels.
13 VDD_D power_in Internal supply pin.
14 VSS_D power_in Ground pin.
15 CE input Transmitter enable input, multiplexed as an anti-tamper control signal.
16 CSN input SPI chip-select input; the SPI interface is active when CSN goes from high to low.
17 SCK input SPI clock input, also multiplexed as the key-transmit and replacement-transmit control signal.
18 MOSI input SPI data input, also multiplexed as the key-transmit and replacement-transmit control signal.
19 MISO output SPI data output, which is high-impedance when not outputting data.
20 IRQ output Maskable interrupt output, active low.
21 VDD power_in Power supply pin.
22 SDA bidirectional I2C data line for the external temperature sensor; a pull-up resistor to the supply is required even when no external sensor is used.
23 SCL output I2C clock line for the external temperature sensor.
24 XO output 16 MHz crystal oscillator output.
25 XI input 16 MHz crystal oscillator input.
26 VDD_PA power_out Supply output pin that powers the internal PA, +1.8 V.
27 RFP passive RF antenna interface 1, paired with RFN.
28 RFN passive RF antenna interface 2, paired with RFP.
29 VSS power_in Ground (0 V).
30 VDD power_in Power supply pin.
31 IREF input Reference current input.
32 NTC_ADC input NTC acquisition analog input.
33 EP passive Exposed pad (from the footprint; not named in the datasheet pin table).

Key specifications

Parameter Value
Manufacturer Nanjing Zhongke Microelectronics
Package QFN-32-EP(4x4)
Category RF And Wireless
Pins 33

Electrical characteristics

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

Parameter Symbol Min Typ Max Unit Conditions Page
Supply voltage (absolute maximum) VDD -0.3 3.6 V 63
Input voltage VI -0.3 5.25 V 63
Total power dissipation 100 mW 63
Operating temperature range -40 85 ℃ 63
Storage temperature (transmitter section) -40 125 ℃ 63
Supply voltage range VDD 1.9 3.6 V 63
DC supply voltage (receiver absolute maximum) VCC -0.5 3.6 V 65
Input pin voltage (receiver absolute maximum) VIN -0.5 3.6 V 65
Input current (latch-up immunity) ISOURCE -100 100 mA 65
ESD ESD -2 2 kV HBM 65
Total power dissipation (all inputs and outputs, receiver) Pt 0.07 mW 65
Storage temperature (receiver section) Tstrg -65 150 ℃ 65
Package body temperature Tbody 260 ℃ 65
Relative humidity, non-condensing RHNC 5 85 % 65
Supply voltage (recommended operating) VCC 2.4 3 3.6 V 65
Ambient temperature (recommended operating) TAMB -40 85 ℃ 65
RF frequency range FOP 2400 2525 MHz 64
RF channel spacing (minimum at 2 Mbps) FCH 2 MHz 2Mpbs 64
Modulation frequency deviation (2 Mbps) ΔFMOD(2Mbps) -330 330 KHz 64
Modulation frequency deviation (1 Mbps / 250 kbps) ΔFMOD(1M/250Kbps) -175 175 KHz 64
GFSK data rate RGFSK 250 2000 Kbps 64
RF output power PRF -3 14 dBm 64
Crystal frequency deviation ΔF -20 20 ppm 64

CAD (KiCad official)

  • Symbol: Si24R2H
  • Footprint: Package_DFN_QFN:QFN-32-1EP_4x4mm_P0.4mm_EP2.9x2.9mm
  • 3D model: QFN-32-EP(4x4) (KiCad packages3D, STEP)
  • 3D model files: si24r2h-etched.step / si24r2h-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); si24r2h.step / si24r2h.glb are the bare package body.

Provenance

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

  • Datasheet: Nanjing Zhongke Microelectronics datasheet (78 pp, sha256 bd940be63ea758c7, retrieved 2026-10-17, tier: lcsc)
  • Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
  • 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