EV-131 - Skyworks Solutions, Inc.

EV-131
AAT4295 EVAL: Single RGB Controller
Introduction
The AAT4295 EVAL board demonstrates the operation of the AAT4295 SmartSwitch™. This device has three
low side N-channel load switches which are serially controlled. The AAT4295 operates from 1.8V to 5.5V, making it ideal for use in 2.5V, 3.3V, or 5V systems as well as systems powered by lithium-ion/polymer batteries.
For demonstration purposes, an AAT3110 voltage doubling charge pump has been incorporated to provide a
regulated voltage source to power the system load, which is an RGB LED.
The AAT4295 is controlled by an S2Cwire™ (Simple Serial Control™) interface with easy control and efficiency.
The device is enabled with the desired switch configuration after a short set of data pulses is sent to the
EN/SET input and holding the line pulled to a logic high. In the enabled state, the AAT4295 typically consumes
less than 3µA of quiescent current. When EN/SET is pulled to a logic low, the device is disabled and each output switch is placed in a high impedance open state. The switch resistance of the low side N-channel MOSFET switches is approximately 2Ω.
This document describes the evaluation board and its accompanying user interface. In addition, a brief
“Getting Started” section is included to help the user begin operating the evaluation board. A schematic of the
complete circuit and the actual board layout are also included in the documentation. For additional information, please consult the AAT4295 product datasheet.
Schematic
VCC
R9
1K
02 1
4 3
5
02 1
4 3
5
02 1
4 3
5
02 1
4 3
5
02 1
4 3
5
R10
1K
R11 R12 R13
1K 1K
1K
1
2
3
4
SW1
SW2
C1
1µF
U3
VDD
GP5
GP4
GP3
VSS
GP0
GP1
GP2
8
7
6
5
PIC12F675
SW3
Off
SW4
3
SW5
On
2
2.7V - 5V
DC+
DC-
1
J1
U1
1
2
3
4
C3
10µF
VOUT C+
GND VIN
GND
CGND SHDN
C2
1µF
8
7
6
5
U2
VCC
R7
100K
1
2
3
4
VIN OUT3
N/C OUT2
N/C OUT1
EN
GND
8
7
6
5
G
D2
R3
70
B
D6
R
D1
R2
68
C4
10µF
100K
R8
AAT3110
B
RGB 1 D3
VCC
R1
130
G
D5
R6
70
R
D4
R5
68
RGB 2
R4
130
AAT4295
Figure 1: Evaluation Board Schematic.
EV-131.2007.01.1.0
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EV-131
AAT4295 EVAL: Single RGB Controller
Getting Started
An external power supply is required; connect the positive terminal to DC+ and the negative terminal to DC-.
The power supply voltage level can be set anywhere between 1.8V and 5.5V. To simulate operation from an LiIon battery source, set the power supply to 3.6V. After applying power to the board, ensure that the jumper J1
is in the ON position.
There are five momentary push button switches on the board, labeled SW1 through SW5. After a switch or
combination of switches are pressed and released, the on-board microcontroller will send the corresponding
S2Cwire programming data to the AAT4295's EN/SET pin. The AAT4295 output settings table can be found in
the product datasheet (Table 1, page 9). Two common Anode type RGB are used for system load. The
AAT4295’s low-side switches connect each red, green and blue LED to ground with a series ballast resistor to
control the forward current through the LED. The circuit is typically used for fashion lighting applications in
portable products such as mobile phone handsets.
By pressing SW1, all outputs should be turned on. All outputs are reset and RGBs should turn off by pressing
SW5 once.
Holding switches SW1 and SW5 together for longer than 1.5 seconds activates the auto cycling mode through
the microcontroller. The microcontroller will submit a burst of edges, pause, and submit another burst of edges
and so on. It starts by submitting 8 edges, then submitting 7 edges, and so on, submitting 1 edge at the end.
The two RGB LEDs should blink three times before the sequence of auto-cycling. Other detailed operations
are described in Table 1.
User Interface Functionality
Switch(es) Pushed
SW1
SW2
SW3
SW4
SW5
SW1 + SW5
Description
[Push/Release once] Turn on all. (RGB becomes White LED)
[Push/Release once] Toggle On/Off of S1 (red LED).
[Push/Release once] Toggle On/Off of S2 (green LED).
[Push/Release once] Toggle On/Off of S3 (blue LED).
[Push/Release once] Reset: Turn off all.
[Push/Release together] Auto Cycling. Blinks (On/Off) for three times and goes into
Binary-decrement mode for 3 times.
Table 1: User Interface Functionality
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EV-131.2007.01.1.0
EV-131
AAT4295 EVAL: Single RGB Controller
Printed Circuit Board
Figure 2: AAT4295 Evaluation Board Top Layer (not to scale).
Figure 3: AAT4295 Evaluation Board Bottom Layer (not to scale).
EV-131.2007.01.1.0
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EV-131
AAT4295 EVAL: Single RGB Controller
AAT4295 EVAL Component Listing
Component
U1
U2
U3
SW1 - SW5
R1, R4
R2, R5
R3, R6
R7
R8
R9 - R12
C3, C4
C2
C1
RGB1, RGB2
J1
Part Number
Description
Manufacturer
AAT4295IJS
AAT3110IJS
PIC12F675
Single RGB Controller; SC70JW-8 Package
Regulated Charge Pump, SC70JW-8 Package
8-bit CMOS, FLASH-based µC; 8-pin PDIP
Package
Switch Tact, SPST, 5mm
130Ω, 1%, 1/4W; 0805
68Ω, 1%, 1/4W; 0805
70Ω, 1%, 1/4W; 0805
100KΩ, 5%, 1/4W; 0402
100KΩ, 5%, 1/4W; 0805
1KΩ, 5%, 1/4W; 1206
10µF, 10V, X5R, 10%, 1206
1µF, 6.3V, X7R, 10%, 0603
1µF, 10V, X7R, 10%, 1206
Common Anode RGB
Conn. Header, 2mm zip
AnalogicTech
AnalogicTech
Microchip
PTS645TL50
Chip Resistor
Chip Resistor
Chip Resistor
Chip Resistor
Chip Resistor
Chip Resistor
GRM319R61A106KE19
GRM185R60J105KE21
GRM319R71A105KA01
1615 SMD LED Series
PRPN401PAEN
ITT Industries
Vishay
Vishay
Vishay
Vishay
Vishay
Vishay
Murata
Murata
Murata
Lasemtech
Sullins Electronics
Table 2: AAT4295 Evaluation Board Component Listing.
© Advanced Analogic Technologies, Inc.
AnalogicTech cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AnalogicTech product. No circuit patent licenses, copyrights, mask work rights,
or other intellectual property rights are implied. AnalogicTech reserves the right to make changes to their products or specifications or to discontinue any product or service without notice.
Customers are advised to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. AnalogicTech
warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with AnalogicTech’s standard warranty. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed.
AnalogicTech and the AnalogicTech logo are trademarks of Advanced Analogic Technologies Incorporated. All other brand and product names appearing in this document are registered trademarks or trademarks of their respective holders.
Advanced Analogic Technologies, Inc.
830 E. Arques Avenue, Sunnyvale, CA 94085
Phone (408) 737- 4600
Fax (408) 737- 4611
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EV-131.2007.01.1.0