OEM7720 Interface Connector

Pin	Signal Name	Signal Type	Signal Direction	V_IL Max (V)	V_IH Min (V)	V_OL Max (V)	V_OH Min (V)	Drive (mA)	Description
1	3V3	Power	Input	-	-	-	-	-	3.2 to 5.0 V ±5% supply input
2	3V3	Power	Input	-	-	-	-	-	3.2 to 5.0 V ±5% supply input
3	COM2_TXD	3.3V CMOS	Output	-	-	0.2	3.1	4	COM2 Transmit Data (UART)
4	COM1_TXD	3.3V CMOS	Output	-	-	0.55	2.3	24	COM1 Transmit Data (UART)
5	COM5_TXD/ COM2_RTS	3.3V CMOS	Output	-	-	0.2	3.1	4	This pin is internally multiplexed. COM5_TXD is the default. COM5_TXD: COM5 Transmit Data (UART). COM2_RTS: COM2 Request to Send Optional hardware flow control signal for the COM2 serial port.
6	COM1_RTS	3.3V CMOS	Output	-	-	0.2	3.1	4	COM1 Request to Send Optional hardware flow control signal for the COM1 serial port.
7	GND	Ground	-	-	-	-	-	-	Ground reference
8	GND	Ground	-	-	-	-	-	-	Ground reference
9	COM2_RXD	3.3V CMOS	Input	0.8	1.7	-	-	-	COM2 Receive Data (UART)
10	COM1_RXD	3.3V CMOS	Input	0.8	1.7	-	-	-	COM1 Receive Data (UART)
11	COM5_RXD/ COM2_CTS	3.3V CMOS	Input	0.8	1.7	-	-	-	This pin is internally multiplexed. COM5_RXD is the default. COM5_RXD: COM5 Receive Data (UART). COM2_CTS: COM2 Clear to Send Optional hardware flow control signal for the COM2 serial port.
12	COM1_CTS	3.3V CMOS	Input	0.8	1.7	-	-	-	COM1 Clear To Send Optional hardware flow control signals for the COM1 serial port.
13	COM4_RXD	3.3V CMOS	Input	0.8	1.7	-	-	-	COM4 Receive Data (UART)
14	COM3_RXD	3.3V CMOS	Input	0.8	1.7	-	-	-	COM3 Receive Data (UART)
15	STATUS_GREEN	3.3V CMOS	Output	-	-	0.2	3.1	4	Used to indicate the state of the receiver or provide error codes. These outputs provide the same information as the Status Indicator LED (see Status LED). STATUS_GREEN high and STATUS_RED low represents a Green LED. STATUS_GREEN high and STATUS_RED high represents a Yellow LED. STATUS_GREEN low and STATUS_RED high represents a Red LED.
16	STATUS_RED	3.3V CMOS	Output	-	-	0.2	3.1	4
17	EVENT_OUT1	3.3V CMOS	Output	-	-	0.2	3.1	8	EVENT1 (Mark1) Output Rising edge triggered. Outputs a user-specified timing signal. Can be synchronized with PPS. Supports Variable Frequency Output function.
18	ME_RDY	3.3V CMOS	Output	-	-	0.2	3.1	4	Receiver Ready (Active High) Indicates to the host system that the receiver is ready to receive commands. This signal is not asserted while booting or during a reset. Internal 2.2 kΩ pull down.
19	COM4_TXD	3.3V CMOS	Output	-	-	0.2	3.1	4	COM4 Transmit Data (UART)
20	COM3_TXD	3.3V CMOS	Output	-	-	0.2	3.1	4	COM3 Transmit Data (UART)
21	ERROR	3.3V CMOS	Output	-	-	0.2	3.1	4	Error Indicator (Active High) Normally low. A high output on this pin indicates that the receiver is in an error state. Internal 2.2 kΩ pull down.
22	POS_VALID	3.3V CMOS	Output	-	-	0.2	3.1	4	Position Valid Output (Active High) A high output on this pin indicates that the receiver has computed a valid GNSS position. Internal 10 kΩ pull down.
23	EVENT_OUT3	3.3V CMOS	Output	-	-	0.2	3.1	8	EVENT3 (Mark3) Output Rising edge triggered. Outputs a user-specified timing signal. Can be synchronized with PPS. Supports Variable Frequency Output function.
24	PPS	3.3V CMOS	Output	-	-	0.55	2.3	24	Pulse Per Second output This signal defaults to one pulse per second but may be altered across a wide range of frequencies using software commands. Edges can be synchronized to GNSS time reference.
25	EVENT_OUT4	3.3V CMOS	Output	-	-	0.2	3.1	8	EVENT4 (Mark4) Output Rising edge triggered. Outputs a user-specified timing signal. Can be synchronized with PPS. Supports Variable Frequency Output function.
26	EVENT_OUT2	3.3V CMOS	Output	-	-	0.2	3.1	8	EVENT2 (Mark2) Output Rising edge triggered. Outputs a user-specified timing signal. Can be synchronized with PPS. Supports Variable Frequency Output function.
27	GND	Ground	-	-	-	-	-	-	Ground reference
28	GND	Ground	-	-	-	-	-	-	Ground reference
29	EVENT_IN2	3.3V CMOS	Input	0.8	1.7	-	-	-	EVENT2 (Mark2) input Rising or falling edge triggered. This input is used to provide a position or time data log based on an external trigger. Internal 10 kΩ pull up.
30	EVENT_IN1	3.3V CMOS	Input	0.8	1.7	-	-	-	EVENT1 (Mark1) input Rising or falling edge triggered. This input is used to provide a position or time data log based on an external trigger. Internal 10 kΩ pull up.
31	EVENT_IN4	3.3V CMOS	Input	0.8	1.7	-	-	-	EVENT4 (Mark4) input Rising or falling edge triggered. This input is used to provide a position or time data log based on an external trigger. Internal 10 kΩ pull up.
32	EVENT_IN3	3.3V CMOS	Input	0.8	1.7	-	-	-	EVENT3 (Mark3) input Rising or falling edge triggered. This input is used to provide a position or time data log based on an external trigger. Internal 10 kΩ pull up.
33	GND	Ground	-	-	-	-	-	-	Ground reference
34	GND	Ground	-	-	-	-	-	-	Ground reference
35	CAN2_RXD	3.3V CMOS	Input	0.8	1.7	-	-	-	CAN2 Receive Data This is a CMOS-level signal, requiring an external CAN transceiver.
36	CAN1_TXD	3.3V CMOS	Output	-	-	0.2	3.1	4	CAN1 Transmit Data This is a CMOS-level signal, requiring an external CAN transceiver.
37	CAN2_TXD	3.3V CMOS	Output	-	-	0.2	3.1	4	CAN2 Transmit Data This is a CMOS-level signal, requiring an external CAN transceiver.
38	CAN1_RXD	3.3V CMOS	Input	0.8	1.7	-	-	-	CAN1 Receive Data This is a CMOS-level signal, requiring an external CAN transceiver.
39	I2C_SDA	3.3V CMOS Open drain	I/O	0.7	2.0	0.4	2.9	-	I2C data line Open drain signal with internal 2.2 kΩ pull up to 3.3 V
40	I2C_SCL	3.3V CMOS Open drain	Output	-	-	0.4	3.1	-	I2C clock line Open drain signal with internal 2.2 kΩ pull up to 3.3 V
41	SPI_MOSI	3.3V CMOS	Output	-	-	0.2	3.1	4	Serial Peripheral Interface Master Output/Slave Input
42	SPI_nCS	3.3V CMOS	Output	-	-	0.2	3.1	4	Serial Peripheral Interface Chip Select (Active Low)
43	SPI_MISO	3.3V CMOS	Input	0.8	1.7	-	-	-	Serial Peripheral Interface Master Input/Slave Output
44	SPI_SCLK	3.3V CMOS	Output	-	-	0.2	3.1	4	Serial Peripheral Interface Serial Clock
45	GND	Ground	-	-	-	-	-	-	Ground reference
46	GND	Ground	-	-	-	-	-	-	Ground reference
47	USB1_D-	Analog	I/O	-	-	-	-	-	USB1 signal. This is one half of the USB1 differential pair. USB1_D+ and USB1_D- must be length-matched and routed as a 90 Ω differential pair.
48	USB0_D+	Analog	I/O	-	-	-	-	-	USB0 signal. This is one half of the USB0 differential pair. USB0_D+ and USB0_D- must be length-matched and routed as a 90 Ω differential pair.
49	USB1_D+	Analog	I/O	-	-	-	-	-	USB1 signal. This is one half of the USB1 differential pair. USB1_D+ and USB1_D- must be length-matched and routed as a 90 Ω differential pair.
50	USB0_D-	Analog	I/O	-	-	-	-	-	USB0 signal. This is one half of the USB0 differential pair. USB0_D+ and USB0_D- must be length-matched and routed as a 90 Ω differential pair.
51	UID	3.3V CMOS	Input	-	-	-	-	-	USB Port Mode Select. Leave this pin floating to put USB0 into Device mode and USB1 into Host mode. Tie this pin to GND to put USB0 into Host mode and USB1 into Device mode. Internal 10 kΩ pull up
52	USB0_VBUS	Power	I/O	3.3	5.25	-	-	-	When the USB port mode is set to Host, this pin is an output. When the USB port mode is set to Device, this pin is an input. Host or Device mode is set using the USB_Port_Mode_Select pin (Pin 51). When an input, requires a voltage between 3.3 V and 5.25 V. When an output, provides 5 V for hosted devices USB0_VBUS is capable of providing up to 200 mA to a hosted USB device. Devices that require more than 200 mA must be powered separately.
53	nRESET_IN	3.3V CMOS	Input	0.8	2.55	-	-	-	Reset Input (Active Low) Resets the OEM7720 receiver card. This pin must be held low for >20 µs while stable power is already applied, to reset the OEM7720 card. It is recommended to hold the nRESET_IN pin low for a >150 ms when initially applying power to the card, giving the power supply time to stabilize before the card starts to boot. Internal 10 kΩ pullup.
54	GND	Ground	-	-	-	-	-	-	Ground reference
55	ETH_LINK_ACT	3.3V CMOS	Output	-	-	0.2	3.1	8	Ethernet Link and Activity LED indicator. Polarity of the indicator signal is low. When there is an active link, the pin is low. When there is activity on the link, the pin outputs a blink signal. Do not use ETH_BIAS to supply the LED.
56	ETH_BIAS	Power	Output	-	-	-	-	-	DC Bias source for the Ethernet magnetics. Do not use ETH_BIAS to supply any other circuitry.
57	ETH_RX+	Analog	Input	-	-	-	-	-	Ethernet Receive One half of the Ethernet receive differential pair. ETH_RX+ and ETH_RX- must be routed as a 100 Ω differential pair.
58	ETH_TX+	Analog	Output	-	-	-	-	-	Ethernet Transmit One half of the Ethernet transmit differential pair. ETH_TX+ and ETH_TX- must be routed as a 100 Ω differential pair.
59	ETH_RX-	Analog	Input	-	-	-	-	-	Ethernet Receive One half of the Ethernet receive differential pair. ETH_RX+ and ETH_RX- must be routed as a 100 Ω differential pair.
60	ETH_TX-	Analog	Output	-	-	-	-	-	Ethernet Transmit One half of the Ethernet transmit differential pair. ETH_TX+ and ETH_TX- must be routed as a 100 Ω differential pair.

1

3V3

Power

Input

-

3.2 to 5.0 V ±5% supply input

2

3V3

Power

Input

-

3.2 to 5.0 V ±5% supply input

3

COM2_TXD

3.3V CMOS

Output

-

0.2

3.1

4

COM2 Transmit Data (UART)

4

COM1_TXD

3.3V CMOS

Output

-

0.55

2.3

24

COM1 Transmit Data (UART)

5

COM5_TXD/ COM2_RTS

3.3V CMOS

Output

-

0.2

3.1

4

This pin is internally multiplexed.
COM5_TXD is the default.

COM5_TXD: COM5 Transmit Data (UART).

COM2_RTS: COM2 Request to Send
Optional hardware flow control signal for the COM2 serial port.

6

COM1_RTS

3.3V CMOS

Output

-

0.2

3.1

4

COM1 Request to Send
Optional hardware flow control signal for the COM1 serial port.

7

GND

Ground

-

Ground reference

8

GND

Ground

-

Ground reference

9

COM2_RXD

3.3V CMOS

Input

0.8

1.7

-

COM2 Receive Data (UART)

10

COM1_RXD

3.3V CMOS

Input

0.8

1.7

-

COM1 Receive Data (UART)

11

COM5_RXD/ COM2_CTS

3.3V CMOS

Input

0.8

1.7

-

This pin is internally multiplexed.
COM5_RXD is the default.

COM5_RXD: COM5 Receive Data (UART).

COM2_CTS: COM2 Clear to Send
Optional hardware flow control signal for the COM2 serial port.

12

COM1_CTS

3.3V CMOS

Input

0.8

1.7

-

COM1 Clear To Send
Optional hardware flow control signals for the COM1 serial port.

13

COM4_RXD

3.3V CMOS

Input

0.8

1.7

-

COM4 Receive Data (UART)

14

COM3_RXD

3.3V CMOS

Input

0.8

1.7

-

COM3 Receive Data (UART)

15

STATUS_GREEN

3.3V CMOS

Output

-

0.2

3.1

4

Used to indicate the state of the receiver or provide error codes.

These outputs provide the same information as the Status Indicator LED (see Status LED).

STATUS_GREEN high and STATUS_RED low represents a Green LED.

STATUS_GREEN high and STATUS_RED high represents a Yellow LED.

STATUS_GREEN low and STATUS_RED high represents a Red LED.

16

STATUS_RED

3.3V CMOS

Output

-

0.2

3.1

4

17

EVENT_OUT1

3.3V CMOS

Output

-

0.2

3.1

8

EVENT1 (Mark1) Output
Rising edge triggered.

Outputs a user-specified timing signal. Can be synchronized with PPS. Supports Variable Frequency Output function.

18

ME_RDY

3.3V CMOS

Output

-

0.2

3.1

4

Receiver Ready
(Active High)

Indicates to the host system that the receiver is ready to receive commands.

This signal is not asserted while booting or during a reset.

Internal 2.2 kΩ pull down.

19

COM4_TXD

3.3V CMOS

Output

-

0.2

3.1

4

COM4 Transmit Data (UART)

20

COM3_TXD

3.3V CMOS

Output

-

0.2

3.1

4

COM3 Transmit Data (UART)

21

ERROR

3.3V CMOS

Output

-

0.2

3.1

4

Error Indicator
(Active High)

Normally low. A high output on this pin indicates that the receiver is in an error state.

Internal 2.2 kΩ pull down.

22

POS_VALID

3.3V CMOS

Output

-

0.2

3.1

4

Position Valid Output
(Active High)

A high output on this pin indicates that the receiver has computed a valid GNSS position.

Internal 10 kΩ pull down.

23

EVENT_OUT3

3.3V CMOS

Output

-

0.2

3.1

8

EVENT3 (Mark3) Output
Rising edge triggered.

Outputs a user-specified timing signal. Can be synchronized with PPS. Supports Variable Frequency Output function.

24

PPS

3.3V CMOS

Output

-

0.55

2.3

24

Pulse Per Second output

This signal defaults to one pulse per second but may be altered across a wide range of frequencies using software commands. Edges can be synchronized to GNSS time reference.

25

EVENT_OUT4

3.3V CMOS

Output

-

0.2

3.1

8

EVENT4 (Mark4) Output
Rising edge triggered.

Outputs a user-specified timing signal. Can be synchronized with PPS. Supports Variable Frequency Output function.

26

EVENT_OUT2

3.3V CMOS

Output

-

0.2

3.1

8

EVENT2 (Mark2) Output
Rising edge triggered.

Outputs a user-specified timing signal. Can be synchronized with PPS. Supports Variable Frequency Output function.

27

GND

Ground

-

Ground reference

28

GND

Ground

-

Ground reference

29

EVENT_IN2

3.3V CMOS

Input

0.8

1.7

-

EVENT2 (Mark2) input

Rising or falling edge triggered. This input is used to provide a position or time data log based on an external trigger.

Internal 10 kΩ pull up.

30

EVENT_IN1

3.3V CMOS

Input

0.8

1.7

-

EVENT1 (Mark1) input

Rising or falling edge triggered. This input is used to provide a position or time data log based on an external trigger.

Internal 10 kΩ pull up.

31

EVENT_IN4

3.3V CMOS

Input

0.8

1.7

-

EVENT4 (Mark4) input

Rising or falling edge triggered. This input is used to provide a position or time data log based on an external trigger.

Internal 10 kΩ pull up.

32

EVENT_IN3

3.3V CMOS

Input

0.8

1.7

-

EVENT3 (Mark3) input

Rising or falling edge triggered. This input is used to provide a position or time data log based on an external trigger.

Internal 10 kΩ pull up.

33

GND

Ground

-

Ground reference

34

GND

Ground

-

Ground reference

35

CAN2_RXD

3.3V CMOS

Input

0.8

1.7

-

CAN2 Receive Data

This is a CMOS-level signal, requiring an external CAN transceiver.

36

CAN1_TXD

3.3V CMOS

Output

-

0.2

3.1

4

CAN1 Transmit Data

This is a CMOS-level signal, requiring an external CAN transceiver.

37

CAN2_TXD

3.3V CMOS

Output

-

0.2

3.1

4

CAN2 Transmit Data

This is a CMOS-level signal, requiring an external CAN transceiver.

38

CAN1_RXD

3.3V CMOS

Input

0.8

1.7

-

CAN1 Receive Data

This is a CMOS-level signal, requiring an external CAN transceiver.

39

I2C_SDA

3.3V CMOS Open drain

I/O

0.7

2.0

0.4

2.9

-

I2C data line

Open drain signal with internal 2.2 kΩ pull up to 3.3 V

40

I2C_SCL

3.3V CMOS Open drain

Output

-

0.4

3.1

-

I2C clock line

Open drain signal with internal 2.2 kΩ pull up to 3.3 V

41

SPI_MOSI

3.3V CMOS

Output

-

0.2

3.1

4

Serial Peripheral Interface Master Output/Slave Input

42

SPI_nCS

3.3V CMOS

Output

-

0.2

3.1

4

Serial Peripheral Interface Chip Select
(Active Low)

43

SPI_MISO

3.3V CMOS

Input

0.8

1.7

-

Serial Peripheral Interface Master Input/Slave Output

44

SPI_SCLK

3.3V CMOS

Output

-

0.2

3.1

4

Serial Peripheral Interface Serial Clock

45

GND

Ground

-

Ground reference

46

GND

Ground

-

Ground reference

47

USB1_D-

Analog

I/O

-

USB1 signal.

This is one half of the USB1 differential pair. USB1_D+ and USB1_D- must be length-matched and routed as a 90 Ω differential pair.

48

USB0_D+

Analog

I/O

-

USB0 signal.

This is one half of the USB0 differential pair. USB0_D+ and USB0_D- must be length-matched and routed as a 90 Ω differential pair.

49

USB1_D+

Analog

I/O

-

USB1 signal.

This is one half of the USB1 differential pair. USB1_D+ and USB1_D- must be length-matched and routed as a 90 Ω differential pair.

50

USB0_D-

Analog

I/O

-

USB0 signal.

This is one half of the USB0 differential pair. USB0_D+ and USB0_D- must be length-matched and routed as a 90 Ω differential pair.

51

UID

3.3V CMOS

Input

-

USB Port Mode Select.

Leave this pin floating to put USB0 into Device mode and USB1 into Host mode.

Tie this pin to GND to put USB0 into Host mode and USB1 into Device mode.

Internal 10 kΩ pull up

52

USB0_VBUS

Power

I/O

3.3

5.25

-

When the USB port mode is set to Host, this pin is an output.

When the USB port mode is set to Device, this pin is an input.

Host or Device mode is set using the USB_Port_Mode_Select pin (Pin 51).

When an input, requires a voltage between 3.3 V and 5.25 V.

When an output, provides 5 V for hosted devices

USB0_VBUS is capable of providing up to 200 mA to a hosted USB device. Devices that require more than 200 mA must be powered separately.

53

nRESET_IN

3.3V CMOS

Input

0.8

2.55

-

Reset Input
(Active Low)

Resets the OEM7720 receiver card. This pin must be held low for >20 µs while stable power is already applied, to reset the OEM7720 card.

It is recommended to hold the nRESET_IN pin low for a >150 ms when initially applying power to the card, giving the power supply time to stabilize before the card starts to boot.

Internal 10 kΩ pullup.

54

GND

Ground

-

Ground reference

55

ETH_LINK_ACT

3.3V CMOS

Output

-

0.2

3.1

8

Ethernet Link and Activity LED indicator.

Polarity of the indicator signal is low. When there is an active link, the pin is low. When there is activity on the link, the pin outputs a blink signal.

Do not use ETH_BIAS to supply the LED.

56

ETH_BIAS

Power

Output

-

DC Bias source for the Ethernet magnetics.

Do not use ETH_BIAS to supply any other circuitry.

57

ETH_RX+

Analog

Input

-

Ethernet Receive

One half of the Ethernet receive differential pair. ETH_RX+ and ETH_RX- must be routed as a 100 Ω differential pair.

58

ETH_TX+

Analog

Output

-

Ethernet Transmit

One half of the Ethernet transmit differential pair. ETH_TX+ and ETH_TX- must be routed as a 100 Ω differential pair.

59

ETH_RX-

Analog

Input

-

Ethernet Receive

One half of the Ethernet receive differential pair. ETH_RX+ and ETH_RX- must be routed as a 100 Ω differential pair.

60

ETH_TX-

Analog

Output

-

Ethernet Transmit

One half of the Ethernet transmit differential pair. ETH_TX+ and ETH_TX- must be routed as a 100 Ω differential pair.

OEM7720 Interface Connector

P1901 Main Connector 60-Pin Socket