External Connector; Power Supplies; Analog Voltage Regulators - Cirrus Logic CDB5378 Manual

2.3.7

External Connector

Power supplies and telemetry signals route to a 20-pin double row connector with 0.1" spacing (J26). This
header provides a compact standardized connection to the CDB5378 external signals.
Pins
1, 2
3, 4
5, 6
7, 8
9, 10
11, 12
13, 14
15, 16
17, 18
19, 20
2.4

Power Supplies

Power is supplied to CDB5378 through banana jacks (J6, J7, J8, J9) or through the external connector
(J26). The banana jacks make separate connections to the EXT_VA-, EXT_VA+, GND, and EXT_VD
power supply nets, which connect to the analog and digital linear voltage regulator inputs. The external
connector makes separate connections only to the EXT_VA-, GND, and EXT_VA+ power supply inputs
and it is required to jumper EXT_VA+ to EXT_VD when powering CDB5378 from the external connector.
The EXT_VA-, EXT_VA+ and EXT_VD power supply inputs have zener protection diodes that limit the
maximum input voltages to +13 V or -13 V with respect to ground. Each input also has 100 uF bulk ca-
pacitance for bypassing and to help settle transients and another 0.01 uF capacitor to bypass high-fre-
quency noise.
2.4.1

Analog Voltage Regulators

Linear voltage regulators create the positive and negative analog power supply voltages to the analog
components on CDB5378. These regulate the EXT_VA+ and EXT_VA- power supply inputs to create the
VA+ and VA- analog power supplies.
Specification
Positive Analog Power Supply
Low Noise Micropower Regulator - Linear Tech
Surface Mount Package Type
Load Regulation, -40 C to +85 C
Quiescent Current, Current @ 100 mA Load
Output Voltage Noise, 10 Hz - 100 kHz
Ripple Rejection, DC - 200 Hz
32
Name
CLK+, CLK-
SYNC+, SYNC-
SCL+, SCL-
SDA+, SDA-
BYP_SDA+, BYP_SDA-
BYP_SCL+, BYP_SCL-
TX, GND
RX, GND
EXT_VA-, GND
EXT_VA+, GND
Signal
Clock Input
Synchronization Input
I2C Clock
I2C Data
I2C Data Bypass
I2C Clock Bypass
UART transmit
UART receive
Negative Power Supply
Positive Power Supply
Value
+2.5 V, +5 V
LT1763CS8
SO-8
+/- 25 mV
40 µA, 2 mA
20 µV
RMS
> 50 dB
CDB5378
DS639DB4