AAT3113ISN-20-T1

AAT3113 ANALOGICTECH | Alldatasheet

Document overview

• Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
• PDF pages: 14

Technical content

Features

• White LED Backlighting
• AAT3113 - 4 Outputs
• AAT3114 - 6 Outputs
• 20mA Full Scale Current
• 32 Position Logarithmic Scale with Digital Control
• Simple Serial Control™ (S 2Cwire™) interface
• Low Noise Constant Frequency Operation
• 33% Less Input Current Than Doubler Charge Pump
• High Accuracy Brightness Matching
• Small Application Circuit
• Regulated Output Current
• Automatic Soft-Start
• VIN Range: 2.7V to 5.5V
• No Inductors
• 600kHz Switching Frequency
• Iq < 1µA in Shutdown
• Temperature Range -40 to 85°C.
• 16-Pin QFN, 12-Pin TSOPJW Package

Applications

• White LED Backlighting
• Programmable Current Source

12-Lead TSOPJW 16 LD 4x4mm QFN (Top View) (Top View) (D5) (D6) C1+ C1- NC OUT C2+ C2- GND AAT3113/4 NC VIN EN/SET C2+ OUT C1- C1+ D D C2- GND VIN EN/SET D D Part Number Function AAT3113-20 4 Diode outputs, 20mA full scale AAT3114-20 6 Diode outputs, 20mA full scale Pin # QFN44-16 TSOPJW-12 Symbol Function 1 7 D2 Current source output 2 6 D3 Current source output 3 5 D4 Current source output

4 N/A D5 Current source output (3114 option only)

5 N/A D6 Current source output (3114 option only)

6 4 C1+ Flying Capacitor 1 + terminal 7 3 C1- Flying Capacitor 1 - terminal

8 N/A NC No Connect

9 2 OUT Charge pump output. Requires 1uF bypass capacitor to ground. 10 1 C2+ Flying Capacitor 2 + terminal 11 12 C2- Flying Capacitor 2 - terminal 12 11 GND Ground

13 N/A NC No Connect

14 10 VIN Input power supply. Requires 1uF bypass capacitor to ground. 15 9 EN/SET Control Pin using S 2Cwire serial interface. 16 8 D1 Current source output 1. Required reference current source. AAT3113/4 High Efficiency 1.5X Fractional Charge Pumps For White LED Applications 2 3113.2004.07.1.4

Absolute Maximum Ratings (TA=25°C unless otherwise noted)

Electrical Characteristics

VIN=3.5V, TA = -40 to 85°C unless otherwise noted. Typical values are at T A = 25°C. Symbol Description Conditions Min Typ Max Units Input Power Supply VIN Operation Range 2.7 5.5 V ICC Operating Current Active, No Load Current 1 2 mA ISHDN Shutdown Current EN=0 1 µA IDX Output Current 3113: 3.0 ≤ VIN ≤ 5.5 TA = 25°C, All 18 20 22 mA3114: 3.2 ≤ VIN ≤ 5.5 Outputs Max Current ∆ID/∆VIN Output Current Line 3.0 ≤ VIN ≤ 5.5 -2 2 %/V Regulation I(D-Match) Current Matching between VD1:Dn=3.6, V IN=3.3V 0.3 % any two outputs η Efficiency V IN=3.5, IOUT(total)=40mA 93 % Charge Pump tSS Soft start time 400 µs FCLK Clock Frequency 300 600 900 KHz EN/SET VEN(L) Enable Threshold Low V IN = 2.7 to 5.5V 0.5 V VEN(H) Enable Threshold High V IN = 2.7 to 5.5V 1.4 V tLO EN/SET low time 0.3 75 µs tHI Minimum EN/SET high time 50 ns tOFF EN/SET Off Timeout 300 500 µs Input Current EN/SET input leakage V IN = 5.5V -1 1 µA Symbol Description Value Units VIN Input Voltage -0.3 to 6 V VOUT Charge Pump Output -0.3 to 6 V VEN/SET EN/SET to GND Voltage -0.3 to 6 V VEN/SET(MAX) Maximum EN/SET to Input Voltage 0.3 V IOUT Maximum DC Output Current (Sum of Iout and D currents) 150 mA θJA Thermal Resistance 37 °C/W TJ Operating Junction Temperature Range -40 to 150 °C AAT3113/4 High Efficiency 1.5X Fractional Charge Pumps For White LED Applications 3113.2004.07.1.4 3

(unless otherwise noted: VIN=3.5V, CIN=COUT=C1=C2=1µF, TA=25°C) Oscillator Frequency vs. Temperature 610 620 630 640 650 660 670 680 690 700 710 -40 -20 0 20 40 60 80 100 Temperature (°C) FOSC (kHz) Shutdown Current vs. Temperature 0.001 0.010 0.100 1.000 -40 -20 0 20 40 60 80 100 Temperature (°C) Shutdown Current (µA) Efficiency vs. Load Current 80% 82% 84% 86% 88% 90% 92% 94% 96% 0 20 40 60 80 100 120 Load Current (mA) Efficiency (%) Quiescent Current vs. Supply Voltage 0.6 0.7 0.8 0.9 1.0 1.1 1.2 Supply Voltage (V) IQ (mA) Efficiency vs. Supply Voltage 60% 65% 70% 75% 80% 85% 90% 95% 100% Supply Voltage (V) Efficiency120 mA 80 mA 60 mA 40 mA 30 mA 20 mA Quiescent Current vs. Temperature 0.860 0.880 0.900 0.920 0.940 0.960 0.980 1.000 -40 -20 0 20 40 60 80 100 Temperature (°C) IQ (mA) AAT3113/4 High Efficiency 1.5X Fractional Charge Pumps For White LED Applications 4 3113.2004.07.1.4

(unless otherwise noted: VIN=3.5V, CIN=COUT=C1=C2=1µF, TA=25°C) VIH and VIL vs. VIN 0.750 0.775 0.800 0.825 0.850 0.875 0.900 0.925 0.950 0.975 1.000 VIN (V) VIH and VIL (V) VIH VIL IDIODE vs. VDIODE 100 120 140 VDIODE (V) IDIODE (mA) IDIODE Response -9dB to -10dB 10µs/div ENSET (2V/div) IDIODE -9 dB 0 dB -10 dB -31 dB IDIODE vs. VIN 100 120 140 3.0 3.5 4.0 4.5 VIN (V) IDIODE (mA) IDIODE Response -31dB to 0dB 10 µs/div ENSET (2V/div) IDIODE -31 dB 0 dB Normalized IDIODE vs. Temperature 0.950 0.960 0.970 0.980 0.990 1.000 1.010 1.020 -40 -20 0 20 40 60 80 100 Temperature (°C) IDIODE AAT3113/4 High Efficiency 1.5X Fractional Charge Pumps For White LED Applications 3113.2004.07.1.4 5

(unless otherwise noted: VIN=3.5V, CIN=COUT=C1=C2=1µF, TA=25°C) 120mA Load Characteristics 1µs/div 20mV/div IN OUT VDIODE 80mA Load Characteristics 1µs/div 20mV/div IN OUT VDIODE 60mA Load Characteristics 1µs/div 20mV/div IN OUT VDIODE 40mA Load Characteristics 1µs/div 10mV/div IN OUT VDIODE Turn-Off 200µs/div ENSET (2V/div) OUT (5V/div) VDIODE (5V/div) IIN (50mA/div) Turn-On 100µs/div ENSET (2V/div) OUT (5V/div) VDIODE (2V/div) IIN (50mA/div) AAT3113/4 High Efficiency 1.5X Fractional Charge Pumps For White LED Applications 6 3113.2004.07.1.4

1.5X Charge Pump S2Cwire Interface 32x8 bit ROM Current Mode DAC VIN C1+ C1- C2+ C2- OUT GND * AAT3114 only EN/SET D5* D6* AAT3113/4 High Efficiency 1.5X Fractional Charge Pumps For White LED Applications 3113.2004.07.1.4 7 Functional Description The AAT3113/4 is a high efficiency 1.5X fractional charge pump device intended for white LED back light applications. The fractional charge pump con- sists of a linear regulator followed by a 1.5X charge pump. The AAT3113/4 requires only four external components: two 1µF ceramic capacitors for the charge pump flying capacitors (C1 and C2), one 1µF ceramic capacitor for C IN, and one 0.33µF to 1µF ceramic capacitor for COUT. The charge pump output is converted into four or six constant current outputs (D1 to D4 or D6) to drive four or six individ- ual LEDs with a maximum of 20mA each. The cur- rent source output magnitude is controlled by the EN/SET serial data S 2C interface. The interface records rising edges of the EN/SET pin, and decodes them into 32 individual current level set- tings each 1dB apart (see Current Level Settings below). Code 32 is full scale, and Code 1 is full scale attenuated by 31dB. The modulo 32 interface wraps states back to state 1 after the 32nd clock. With each EN/SET pulse, the output current increas- es by 1dB. To decrease the output current by 1dB, 31 EN/SET clock pulses are required. The counter can be clocked at speeds up to 1Mhz, so intermedi- ate states are not visible. The first rising edge of EN/SET enables the IC and initially sets the output LED current to -31dB, the lowest setting equal to 525µA. Once the final clock cycle is input for the desired brightness level, the EN/SET pin is held high to maintain the device output current at the pro- grammed level. The device is disabled 500µs after the EN/SET pin transitions to a logic low state.

High Efficiency 1.5X Fractional Charge Pumps For White LED Applications 8 3113.2004.07.1.4 Applications Information Current Level Settings LED current level is set via the serial interface according to a logarithmic scale where each code is 1dB greater than the previous code. In this man- ner, the LED brightness appears linear with each increasing code. Current Levels (mA) Code 20 mA max 17 3.529 18 4.000 19 4.471 20 5.020 21 5.647 22 6.353 23 7.059 24 7.922 25 8.941 26 10.039 27 11.216 28 12.627 29 14.118 30 15.843 31 17.804 32 20.000 Code 20 mA max 1 0.549 2 0.627 3 0.706 4 0.784 5 0.863 6 1.020 7 1.098 8 1.255 9 1.412 10 1.569 11 1.804 12 1.961 13 2.275 14 2.510 15 2.824 16 3.137 Normalized Current Level Settings 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1 2 3 4 5 6 7 8 9 1 01 11 21 31 41 51 61 71 81 92 02 12 22 32 42 52 62 72 82 93 03 13 2 Code Normalized Current to Full Scale

The current source output magnitude is controlled by the EN/SET pin using AnalogicTech’s Simple Serial Control (S 2Cwire) interface. The interface records rising edges of the EN/SET pin, and decodes them into 32 individual current level set- tings each 1dB apart. Code 32 is full scale, and Code 1 is full scale attenuated by 31dB. The mod- ulo 32 interface wraps states back to state 1 after the 32nd clock, so 1dB of attenuation is achieved by clocking the EN/SET pin 31 times (see graph titled “IDIODE Response -9dB to -10dB” on page 5). The counter can be clocked at speeds up to 1Mhz, so intermediate states are not visible. The first rising edge of EN/SET enables the IC and ini- tially sets the output LED current to -31dB, the low- est setting equal to 525µA. Once the final clock cycle is input for the desired brightness level, the EN/SET pin is held high to maintain the device out- put current at the programmed level. The device is disabled 500µs after the EN/SET pin transitions to a logic low state. The EN/SET timing is designed to accommodate a wide range of data rates. After the first rising edge of EN/SET, the charge pump is enabled and reach- es full capacity after the soft start time (t SS). During the soft start time, multiple clock pulses may be entered on the EN/SET pin to set the final output current level with a single burst of clocks. Alternatively, the EN/SET clock pulses may be entered one at a time to gradually increase the LED brightness over any desired time period. A constant current is sourced as long as EN/SET remains in a logic high state. The current source outputs are switched off after EN/SET has remained in a low state for at least the t OFF timeout period. LED Selection The AAT3113/4 devices are designed to drive white LEDs with forward voltages of less than 4.2V. Since the D1:D6 output current sources are matched with negligible voltage dependence, the LED brightness will be matched regardless of their forward voltage matching. Charge Pump Efficiency The AAT3113/4 is a fractional charge pump. The efficiency (η) can be simply defined as a linear volt- age regulator with an effective output voltage that is equal to one and a half times the input voltage. Efficiency ( η) for an ideal 1.5x charge pump can typically be expressed as the output power divided by the input power. η = P OUT / PIN In addition, with an ideal 1.5x charge pump, the output current may be expressed as 2/3 of the input current. The expression to define the ideal efficiency (η) can be rewritten as: η=P OUT/PIN=(VOUTxIOUT)/(VINx1.5IOUT)=VOUT/1.5VIN η(%) = 100(VOUT / 1.5VIN) For a charge pump with an output of 5 volts and a nominal input of 3.5 volts, the theoretical efficiency is 95%. Due to internal switching losses and IC quies- cent current consumption, the actual efficiency can be measured at 93%. These figures are in close agreement for output load conditions from 1mA to 100mA. Efficiency will decrease as load current drops below 0.05mA or when level of V IN approach- es VOUT. Refer to the Typical Characteristics section for measured plots of efficiency versus input voltage and output load current for the given charge pump output voltage options. AAT3113/4 High Efficiency 1.5X Fractional Charge Pumps For White LED Applications 3113.2004.07.1.4 9 EN/SET Timing EN/SET Code 1 2 3 OFFOFF tHI tLO tOFF

High Efficiency 1.5X Fractional Charge Pumps For White LED Applications 10 3113.2004.07.1.4 Power Efficiency and Device Evaluation: The charge pump efficiency discussion of the previ- ous section only accounts for the efficiency of the charge pump section itself. Due to the unique circuit architecture and design of the AAT3113/14, it is very difficult to measure efficiency in terms of a percent value comparing input power over output power. Since the AAT3113/14 outputs are pure constant cur- rent sources, it is difficult to measure the output volt- age for a given output (D1 to D6) to derive an output power measurement. For any given application, white LED forward voltage levels can differ, yet the output drive current will be maintained as a constant. This makes quantifying output power a difficult task when taken in the context of comparing to other white LED driver circuit topologies. A better way to quantify total device efficiency is to observe the total input power to the device for a given LED current drive level. The best White LED driver for a given application should be based on trade-offs of size, external component count, reliability, operating range and total energy usage...Not just "% efficiency". Capacitor Selection Careful selection of the four external capacitors CIN, C1, C2, C OUT is important because they will affect turn on time, output ripple and transient per- formance. Optimum performance will be obtained when low ESR (<100m Ω) ceramic capacitors are used. In general, low ESR may be defined as less than 100mΩ. A capacitor value of 1µF for all four capacitors is a good starting point when choosing capacitors. If the LED current sources are only programmed for minimal current levels, then the capacitor size may be decreased. Capacitor Characteristics Ceramic composition capacitors are highly recom- mended over all other types of capacitors for use with the AAT3113/4 products. Ceramic capacitors offer many advantages over their tantalum and alu- minum electrolytic counterparts. A ceramic capaci- tor typically has very low ESR, is lowest cost, has a smaller PCB footprint and is non-polarized. Low ESR ceramic capacitors help maximize charge pump transient response. Since ceramic capacitors are non-polarized, they are not prone to incorrect connection damage. Equivalent Series Resistance (ESR): ESR is an important characteristic to consider when selecting a capacitor. ESR is a resistance internal to a capacitor, which is caused by the leads, internal connections, size or area, material composition and ambient temperature. Capacitor ESR is typi- cally measured in milliohms for ceramic capacitors and can range to more than several ohms for tan- talum or aluminum electrolytic capacitors. Ceramic Capacitor Materials: Ceramic capacitors less than 0.1 µF are typically made from NPO or COG materials. NPO and COG materials typically have tight tolerance and are stable over tempera- ture. Large capacitor values are typically com- posed of X7R, X5R, Z5U or Y5V dielectric materi- als. Large ceramic capacitors, typically greater than 2.2µF are often available in low cost Y5V and Z5U dielectrics, but large capacitors are not required in the AAT3113/4 application. Capacitor area is another contributor to ESR. Capacitors that are physically large will have a lower ESR when compared to an equivalent material smaller capacitor. These larger devices can improve circuit transient response when compared to an equal value capacitor in a smaller package size. Thermal Protection The AAT3113/4 have a thermal protection circuit that will shut down the charge pump and current outputs if the die temperature rises above the ther- mal limit. However, thermal resistance of the QFN package is so low, that if, in the case of the AAT3114, all six outputs are shorted to ground at maximum 20mA output level, the die temperature will not rise sufficiently to trip the thermal protection. The thermal protection will only trip if C OUT is short- ed to ground and the ambient temperature is high. AAT3114 Input Power vs. LED Current 100 200 300 400 500 600 700 0 20 40 60 80 100 120 140 Output (LED) Current (mA) Input Power (mW) VIN = 3.6V

Typical AAT3113 Application Circuit: CIN 1µFVBATTERY COUT 1µF EN/SET 1µF 1µF D4 D3 D2 D1 VIN VOUT C1+ C1- C2+ C2- EN/SET GND AAT3113 ON/1 THI > 50ns 50ns minimum to enable300ns < TLO < 75µs 23456 n (n < =32) OFF Enable / Disable / LED Brightness Level Set Data Input AAT3113/4 High Efficiency 1.5X Fractional Charge Pumps For White LED Applications 3113.2004.07.1.4 11

Driving White LED display module back lights and individual white LED's connected in parallel: The AAT3113/14 D1 to D6 outputs are true constant current sources capable of driving up to 20mA each over the operation input voltage range. Since these outputs are true constant current sources, they may be connected in parallel to drive a single power out- put. Any combination of outputs (D1 to D6) may be connected in parallel. The maximum total output current is a sum of how many current sources are parallel connected. This feature is particularly use- ful to power pre-manufactured display modules which are pre-wired with white LED backlights con- nected in a parallel circuit configuration. All output may be connected in parallel to drive groups of LED's as well. The internal current source refer- ence circuit bases feedback from current sensed on the D1 output. For best operation, the only require- ment for this application is the output D1 should always be connected to the load circuit. AAT3113/4 High Efficiency 1.5X Fractional Charge Pumps For White LED Applications 12 3113.2004.07.1.4 AAT3114 application driving a display module with six parallel connected white LEDs: AAT3114 Dual Backlight Control Circuit: CIN 1µFVBATTERY COUT 1µF EN/SET 1µF 1µF D2 D3 VIN VOUT C1+ C1- C2+ C2- EN/SET GND AAT3114 D5 D6 Enable Display Backlight Enable Keyboard Backlight Display Backlight Keyboard Backlight CIN 1µF VBATTERY COUT 1µF EN/SET 1µF 1µF D2 D3 D4 D5 VIN VOUT C1+ C1- C2+ C2- EN/SET GND AAT3114 D6 D1 D6 Display Module RR RRR R Resistor R is optional

Ordering Information

Note: Sample stock is generally held on all part numbers listed in BOLD. Note 1: XYY = assembly and date code.

Package Information

All dimensions in millimeters. 4.000 ± 0.050 Pin 1 Dot By Marking 2.400 ± 0.050 0.600 ± 0.050 4.000 ± 0.050 2.280 REF

0.650 BSC

0.900 ± 0.050 Pin 1 Identification R0.030Max 13 16 0.450 ± 0.050 0.0125 ± 0.0125 0.203 ± 0.025 0.330 ± 0.050 Top View Bottom View Side View Package Marking 1 Part Number (Tape and Reel) QFN44-16 EUXYY AAT3113ISN-20-T1 QFN44-16 FGXYY AAT3114ISN-20-T1 TSOPJW-12 HTXYY AAT3113ITP-20-T1 AAT3113/4 High Efficiency 1.5X Fractional Charge Pumps For White LED Applications 3113.2004.07.1.4 13

All dimensions in millimeters. 0.20 + 0.10 - 0.05 0.055 ± 0.045 0.45 ± 0.15 7° NOM 4° ± 4° 3.00 ± 0.10 2.40 ± 0.10 2.85 ± 0.20 0.15 ± 0.05 0.9625 ± 0.0375 1.00 + 0.10 - 0.065

0.04 REF

0.010 2.75 ± 0.25 AAT3113/4 High Efficiency 1.5X Fractional Charge Pumps For White LED Applications 14 3113.2004.07.1.4 Advanced Analogic Technologies, Inc. 830 E. Arques Avenue, Sunnyvale, CA 94085 Phone (408) 737-4600 Fax (408) 737-4611 AnalogicTech cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AnalogicTech pr oduct. 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 wi thout notice, and advise customers 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 l iability. AnalogicTech warrants performance of its semiconductor products to the specifications applicable at the time of sale in accorda nce with AnalogicTech’s standard warranty. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to support this warranty. Specific tes ting of all parameters of each device is not necessarily performed.