Table of Contents
Advertisement
AD8452
System Demo User Guide
EVALUATION BOARD HARDWARE
SETTING UP THE EVALUATION SYSTEM
Figure 25 to Figure 27 show the analog interface board
schematics, and Figure 17 shows the power module board
schematic.
The analog interface board includes the AD8452 (U7), the
AD7173-8
24-bit Σ-Δ ADC (U10), and the
DAC (U6).
Connector J1, Connector J2, and Connector J3 mate with the
power module board to provide the PWM control signals for
the MOSFET drivers, as well as the battery voltage, the current
signals, and the supply voltage for the analog interface board.
The modular approach of the system allows users to use the
analog interface board with their custom design power module.
Table 1, Table 2, and Table 3 list the header pin names and
functionalities.
The power module board includes an
driver (U1), a high-side and low-side power MOSFET,
switching inductor, and input output capacitors.
Connect the boards as shown in Figure 1.
POWERING THE SYSTEM
The evaluation system requires power from an external dc
power source. The main power input is connected through the
banana terminals labeled J4 and J5 on the analog interface
board. The input voltage to the system can be between a 10 V
minimum and a 30 V maximum, depending on the operating
voltage of the power module board. The standard power
module board, included in this system, allows operation up to
20 V. The input current depends on the desired load current
(that is, battery charge current). To run the board at the rated
10 A charge current into a 5 V load, the input 12 V power
supply must be capable of delivering at least 5 A.
The analog interface board can be powered from the main
power input or from a separate dc supply using the J6 screw
terminal connector. In the default configuration, the analog
interface is powered from the main power input terminals. To
power the analog interface board from an independent 15 V
source, remove Resistor R4 and populate a 0 Ω jumper at R1.
To turn on the board, apply 12 V input power of the correct
polarity between terminals J4 and J5. The light emitting diodes
(LEDs) on the lower left of the analog interface board illuminate,
indicating the analog interface voltage regulators are operating.
The battery or electronic load can be connected to the banana
terminals labeled J8 and J9.
AD5689R
16-bit
ADuM7223
MOSFET
Rev. 0 | Page 5 of 32
AD8452 COMPENSATION NETWORKS
The evaluation system ships configured for connection to a
Chroma 63600 series electronic load. If the electronic load of
the user has a different response, or if the user wants to use the
system with a rechargeable battery, adjust the compensation values
in each of the four AD8452 control loops to ensure system
stability. The online
AD8450/AD8451
at
http://analogplayground.com/AD8450
with compensation by adding the current limit shunt resistance
to the inductor equivalent series resistance (ESR) and entering
the sum in the R
Inductor ESR (Ω) entry box. See the
L
AN-1319
for detailed analysis of the compensation.
SERIAL INTERFACE
The evaluation system uses the serial peripheral interface (SPI)
on the
SDP-S
board to read the current and voltage ADCs, and
to set the current and voltage set points with the
Table 1. J1 Board to Board Connector Pinout
Pin No.
Name
Description
1, 3, 5, 7
Vin+
Supply rail from analog interface board
2, 4, 6, 8
PGND
Power ground
Table 2. J2 Board to Board Connector Pinout
Pin No.
Name
Description
1
GND
Digital ground
2
5 V
Logic supply
3
DL
Low side FET logic signal
4
10 V
Supply for FET drive
5
DH
High side FET logic signal
6
AUX_EN
Control signal to/from analog interface
board
7
GND
Digital ground
8
GND
Digital ground
9
CL+
Inductor current sense (+)
10
CS−
Output current sense (−)
11
CL−
Inductor current sense (−)
12
CS+
Output current sense (+)
Table 3. J3 Board to Board Connector Pinout
Pin No.
Name
Description
1, 3, 5, 7, 9,
Vout+
Output to analog interface board
11, 13, 15
2, 4, 6, 8, 10,
PGND
Power ground
12, 14, 16
UG-1181
compensator design tool
can be used to assist
AD5689R
DAC.
Advertisement
Table of Contents
