Pad Name Description
1 VCC Power supply input, +3.3 to +5.5 Vdc.
2 GND Power supply and signal ground. Connect to the host circuit board ground.
3 PWMA Pulse-width modulated output A. Provides a DAC function when used with an external low-pass filter.
4 PWMB Pulse-width modulated output B. Provides a DAC function when used with an external low-pass filter.
5 GPIO0 Configurable digital I/O port 0. When configured as an output, the power-on state is also configurable.
6 GPIO1 Configurable digital I/O port 1. When configured as an output, the power-on state is also configurable.
7 GPIO2 Configurable digital I/O port 2. When configured as an output, the power-on state is also configurable.
8 GPIO3
Configurable digital I/O port 3. When configured as an output, this high current port can sink up to 20 mA. The
power-on output state is also configurable.
9 GPIO4 Configurable digital I/O port 4. When configured as an output, the power-on state is also configurable.
10 GPIO5 Configurable digital I/O port 5. When configured as an output, the power-on state is also configurable.
11 GND Power supply and signal ground. Connect to the host circuit board ground.
12 LINK/DD Output signal indicating module’s link status in default mode. Also used by JTAG interface as Data Output.
13 /RESET Active low hardware reset. Hold this input low when the power supply is below 2.7 V. In parallel with pad 24.
14 ACT/DC Output signal indicating RF data activity. Also used by JTAG interface as Data Clock Input.
15 NC No connection.
16 ADC REF
Module’s +3.3 V regulated supply, used for ratiometric ADC readings. Current drain on this output should be no
greater than 5 mA.
17 - 20 GND Power supply and signal grounds. Connect to the host circuit board ground.
21 UART_RX Serial data input to UART.
22 UART_TX Serial data output from UART.
23 NC No connection.
24 /RESET Active low hardware reset. Hold this input low when the power supply is below 2.7 V. In parallel with pad 13.
25 ADCX 7- to 12-bit ADC input X. ADC full scale can be referenced to +3.3 V supply or internal +2.5 V reference.
26 ADCY 7- to 12-bit ADC input Y. ADC full scale can be referenced to +3.3 V supply or internal +2.5 V reference.
27 ADCZ 7- to 12-bit ADC input Z. ADC full scale can be referenced to +3.3 V supply or internal +2.5 V reference.
28 GND Power supply and signal ground. Connect to the host circuit board ground.
29 SPI_EN Active-low enable output for SPI bus devices.
30 SPI_SCLK SPI port clock signal.
31 SPI_MOSI SPI port data output.
32 SPI_MISO SPI port data input.
33-34 GND Power supply and signal ground. Connect to the host circuit board ground.
35 NC No connection.
36 GND Power supply and signal ground. Connect to the host circuit board ground.
37 GND RF ground. Connect to the host circuit board ground plane, and to shield when using coaxial cable.
38 RFIO
RF port. Connect the antenna to this port with a 50 Ω stripline or semi-rigid coaxial cable.
39 GND RF ground. Connect to the host circuit board ground plane, and to shield when using coaxial cable.
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©2008 by RF Monolithics, Inc. ZMN2405HP- 5/20/08
ZMN2405HP I/O Pad Descriptions
