AAT2847 Advanced Analog Technology, Inc., AAT2847 Datasheet
AAT2847
Related parts for AAT2847
AAT2847 Summary of contents
Page 1
... The backlight driver in the AAT2847 is a low noise tri- mode DC/DC charge pump converter. Each of the four channels of the backlight driver is capable of delivering up to 20mA of bias currents for white LEDs. The white LED (WLED) backlight bias current matching is 1% which helps provide uniform display brightness ...
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... LED3 current channel input. Connect to the cathode of backlight LED 3. If not used, connect D3 to the OUT pin. Ground. Enable pin for LDOA. Active logic high. AAT2847-EE: Feedback pin of LDOB. Internally regulated at 1.2V. AAT2847-QG/QI: No connection. Do not make any connection to this pin. Exposed pad (bottom). D4 ENB EN/SET ...
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... ChargePump ChargePump TM TM Absolute Maximum Ratings T = 25°C, unless otherwise noted. Pin descriptions below apply to AAT2847-EE (AAT2847-QG/QI) A Symbol Description V [IN, OUT, D1, D2, D3, D4] to GND N V [C1+, C1-, C2+, C2-] to GND N V [LDOA, LDOB, FBA, FBB, EN/SET, ENA, ENB] to GND N T Operating Temperature Range ...
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... EN/SET Input Leakage EN/SET 1. The AAT2847 is guaranteed to meet performance specifications over the –40°C to +85°C operating temperature range is assured by design, characterization and correlation with statistical process controls. 2. Current matching is defined as the deviation of any sink current from the average of all active channels. ...
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... IH(ENA) V Threshold Voltage IH(ENB) I ENA, ENB Input Leakage EN[A/B] 1. The AAT2847 is guaranteed to meet performance specifications over the –40˚C to +85°C operating temperature range is assured by design, characterization and correlation with statistical process controls defined LDOA when LDOA is 98% of nominal 2847 ...
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... Backlight Current Matching vs. Temperature 20.5 19.5 18.5 4.7 5.1 5.5 4.7 5.1 5.5 4.7 5.1 5 PRODUCT DATASHEET PRODUCT DATASHEET AAT2847 AAT2847 (I = 20mA/Channel 4.2V) OUT -40 - Temperature (°C) EN/SET Off Timeout vs. Input Voltage 400 350 -40°C ...
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... PRODUCT DATASHEET PRODUCT DATASHEET AAT2847 AAT2847 Backlight Operating Characteristic (V = 3.7V; 1.5X Mode; 20mA/Channel Load Coupled OUT V DX Time (500ns/div) ...
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... LDOB -1.000 100 1000 PRODUCT DATASHEET PRODUCT DATASHEET AAT2847 AAT2847 Turn On to 1.5X Mode Backlight (20mA/Channel; Address 0, Data EN/SET (2V/div) V OUT (2V/div) V ...
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... PRODUCT DATASHEET PRODUCT DATASHEET AAT2847 AAT2847 LDOA Load Transient Response (V = 3.6V 1.2V) IN LDOA 200mA I LDOA 10mA V LDOA Time (20µs/div) ...
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... EN(A/B) (2V/div) V LDO(A/B) (500mV/div PRODUCT DATASHEET PRODUCT DATASHEET AAT2847 AAT2847 LDOA/LDOB Turn On = 3.6V 1.8V; DC Coupled) LDO(A/B) Time (40µs/div) LDOA/LDOB Turn On = 3.6V 1.2V; DC Coupled) LDO(A/B) Time (40µs/div) 2847 ...
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... LED cathode pin voltage. The voltage threshold for 1X to 1.5X and 1. mode transitions The charge pump in the AAT2847 starts- mode (default); under this condition, if the LED cathode input pin voltage is below V the AAT2847 will transition into TH 1 ...
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... Code Figure 1: LED Current Control Profile. AS Cwire Serial Interface 2 Each white LED channel input on the AAT2847 (D1-D4) is controlled by AnalogicTech’s AS Cwire serial digital inter- 2 face. The AS Cwire interface uses the number of rising 2 edges on the EN/SET pin to address and load the LED configuration registers ...
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... Data 0.5 12 1.0 13 1 Table 5: Independent LED Control Settings— PRODUCT DATASHEET AAT2847 Data T LAT n ≤ off on on off ...
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... ChargePump TM Auto Disable Feature The charge pump in the AAT2847 is equipped with an auto-disable feature for each LED channel. After the IC is enabled and successively starts-up, a test current of 100µA (typical) is forced through each LED channel. The channel will be disabled if the voltage on that particular DX pin does not drop to certain threshold ...
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... The same calculations apply for the AAT2847 in 2X mode 79.6k where for an ideal 2X charge pump, the input current is 60. the output current. The expression for the esti- 30.1k mated ideal efficiency (η) for the AAT2847 in 2X mode is as follows: P LEDs η · ...
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... C5, and C6) should be con- nected as close as possible to the IC. In addition to the external passive components being placed as close as possible to the IC, all traces connecting the AAT2847 should be as short and wide as possible to minimize path resistance and potential coupling. Figure 4: AAT2847 Package Layout. ...
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... PGND C1 OUT C4 C2 LDOA Figure 7: AAT2847 Section Schematic PRODUCT DATASHEET PRODUCT DATASHEET AAT2847 AAT2847 Solder Side Layout. DC+ DC ...
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... GP0 3 GP4 GP1 4 GP3 GP2 PIC12F675 Figure 8: MCU Section Schematic PRODUCT DATASHEET PRODUCT DATASHEET AAT2847 AAT2847 J4 EN/SET LED7 RED 2847 ...
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... Four-Channel Backlight Driver with Dual LDOs Marking LDOB 1 Programmable YLXXY 1.5V 1.8V ZDXYY PRODUCT DATASHEET PRODUCT DATASHEET AAT2847 AAT2847 Part Number (Tape and Reel) 2 AAT2847IML-EE-T1 AAT2847IML-QG-T1 AAT2847IML-QI- ...
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... TQFN34-20 1.55 ± 0.05 Detail "A" Bottom View 0.214 ± 0.036 PRODUCT DATASHEET PRODUCT DATASHEET AAT2847 AAT2847 0.40 ± 0.100 Detail "A" 2847.2008.05.1.2 2847.2008.05.1.2 ...