Cirrus Logic CRD5376 - Manual (Page 28)

CRD5376
28 DS612RD2
version data. Address assignment can be either dynamic or static, depending how the telemetry system
is to be implemented.
Dynamic address assignment uses daisy-chained I2C connections to assign an address to each mea-
surement node. Once a node receives an address, it enables the I2C bypass switches to the next node
so it can be assigned an address.
Static address assignment has a serial number assigned to each node during manufacturing. When
placed in the network the location is recorded and a master list of serial numbers vs. location is main-
tained. Alternately, a location dependent serial number can be assigned during installation.
2.3.5 UART Connection
A UART connection on CRD5376 provides a low-speed standardized connection for telemetry solutions
not using I2C. UART connections are provided for custom programming convenience only and are not
directly supported by the CRD5376 PC evaluation software or microcontroller firmware.
2.3.6 External Connector
Power supplies and telemetry signals route to a 20-pin double row connector with 0.1" spacing (J8). This
header provides a compact standardized connection to the CRD5376 external signals.
2.4 Power Supplies
Power is supplied to CRD5376 through the +3.3 V and -3.3 V voltage inputs on the external connector
(J8), which are typically from an external AC-DC or DC-DC converter. Digital circuitry on CRD5376 is driv-
en directly from the +3.3 V input, while linear regulators create +2.5 V and - 2.5 V analog power supplies
from +3.3 V and -3.3 V.
The +3.3 V and -3.3 V power supply inputs have zener protection diodes that limit the maximum input volt-
ages to +5 V or -5 V with respect to ground. Each input also has 100 uF bulk capacitance for bypassing
and to help settle transients and another 0.01 uF capacitor to bypass high frequency noise.
Specification Value
UART Connections, 2 wires each
TX/GND, RX/GND
Pins Name Signal
1, 2 CLK+, CLK- Clock Input
3, 4 SYNC+, SYNC- Synchronization Input
5, 6 SCL+, SCL- I2C Clock
7, 8 SDA+, SDA- I2C Data
9, 10 BYP_SDA+, BYP_SDA- I2C Data Bypass
11, 12 BYP_SCL+, BYP_SCL- I2C Clock Bypass
13, 14 TX, GND UART transmit
15, 16 RX, GND UART receive
17, 18 -3.3V, GND Negative Power Supply
19, 20 +3.3V, GND Positive Power Supply