2.12 - DB37 [UE9 Datasheet]
The DB37 connector brings out analog inputs, analog outputs, FIO, and other signals. Some signals appear on both the DB37 connector and screw terminals, so care must be taken to avoid a short circuit.
Table 2.12-1. DB37 Connector Pinouts
DB37 Pinouts |
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1 | GND | 14 | AIN9 | 27 | Vs |
2 | PIN2 (TX/200uA) | 15 | AIN7 | 28 | Vm+ |
3 | FIO6 | 16 | AIN5 | 29 | DAC1 |
4 | FIO4 | 17 | AIN3 | 30 | GND |
5 | FIO2 | 18 | AIN1 | 31 | AIN12 |
6 | FIO0 | 19 | GND | 32 | AIN10 |
7 | MIO1 | 20 | PIN20 (RX / 10uA) | 33 | AIN8 |
8 | GND | 21 | FIO7 | 34 | AIN6 |
9 | Vm- | 22 | FIO5 | 35 | AIN4 |
10 | GND | 23 | FIO3 | 36 | AIN2 |
11 | DAC0 | 24 | FIO1 | 37 | AIN0 |
12 | AIN13 | 25 | MIO0 |
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13 | AIN11 | 26 | MIO2 |
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Figure 2.12-2. Standard DB37 pin numbers looking into the female connector on the UE9
GND, Vs, AIN, DAC, FIO, and MIO are all described earlier.
Vm+/Vm- are bipolar power supplies intended to power external multiplexer ICs such as the MAX4051A (maxim-ic.com). The multiplexers can only pass signals within their power supply range, so Vm+/Vm- can be used to pass bipolar signals. Nominal voltage is ±5.8 volts at no load and ±5.6 volts at 1 mA. Both lines have a 100 ohm source impedance, and are designed to provide 1 mA or less. This is the same voltage supply used internally by the UE9 to bias the analog input amplifier and multiplexers. If this supply is loaded more than 1 mA, the voltage can droop to the point that the maximum analog input range is reduced. If this supply is severely overloaded (e.g. short circuited), then damage could eventually occur.
PIN2/PIN20 (TX0/RX0) bring out the UART transmit and receive lines on the UE9, but on other devices they bring out current sources.