Data Sheet FEATURES Drives 4 LEDs from a.6 V to 5.5 V (Li-Ion) input supply /.5 / fractional charge pump to maximize power efficiency 0.3% typical LED current matching Up to 88% power efficiency over Li-Ion range Powers main and sub display LEDs with individual shutdown Package footprint only 9 mm (3 mm 3 mm) Package height only 0.55 mm Low power shutdown mode Shutdown function Soft start limiting in-rush current APPLICATIONS Cellular phones with main and sub displays White LED backlighting Camera flash/strobes and movie light applications Micro TFT color displays DSC PDAs Four White LED Backlight Driver GENERAL DESCRIPTION The uses charge pump technology to provide the power to drive up to four LEDs. The LEDs are used for backlighting a color LCD display that has regulated constant current for uniform brightness intensity. The main display can use up to three LEDs, and the sub display uses one LED. The CTRL and CTRL digital input control pins control the shutdown operation and the brightness of the main and sub displays. To maximize power efficiency, the charge pump can operate in,.5, or mode. The charge pump automatically switches among /.5 / modes, based on the input voltage, to maintain sufficient drive for the LED anodes at the highest power efficiency. Improved brightness matching of the LEDs is achieved by a feedback pin that senses individual LED current with a typical matching accuracy of 0.3%. FUNCTIONAL BLOCK DIAGRAM C µf C µf C4 4.7µF CHARGE PUMP /.5 / MODE C3.µF MAIN SUB CTRL CTRL CONTROL LOGIC V REF OSC FB FB FB3 FB4 R SET LED CONTROL CIRCUIT CONTROL CONTROL CONTROL 3 CONTROL 4 CONTROLLED SINKS 05050-00 Figure. Rev. D Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 906, Norwood, MA 006-906, U.S.A. Tel: 78.39.4700 004 07 Analog Devices, Inc. All rights reserved. Technical Support www.analog.com
Data Sheet TABLE OF CONTENTS Features... Applications... General Description... Functional Block Diagram... Revision History... Specifications... 3 Absolute Maximum Ratings... 4 Thermal Characteristics... 4 ESD Caution... 4 Pin Configuration and Function Descriptions... 5 Typical Performance Characteristics... 6 Theory of Operation... 9 Automatic Gain Control... 0 Brightness Control with a Digital PWM Signal... 0 LED Brightness Control Using a PWM Signal Applied to VPWM... LED Brightness Control Using a DC Voltage Applied to VBRIGHT... Applications... 3 Layout Considerations and Noise... 3 White LED Shorting... 3 Driving Four LEDs in the Main Display Only... 3 Driving Fewer than Four LEDs... 3 Using Smaller Capacitor Values... 4 Power Efficiency... 5 Outline Dimensions... 6 Ordering Guide... 6 REVISION HISTORY 3/07 Rev. C to Rev. D Changed CP-6-3 to CP-6-... Throughout Changes to Figure... 5 Updated Outline Dimensions... 6 Changes to Ordering Guide... 6 /0 Rev. B to Rev. C Changes to Figure 4... 7 4/00 Rev. A to Rev. B Removed CP-6- Package... Universal Change to Figure... 5 Change to Figure 6... 6 Changes to Figure 4... 7 Changes to Figure 5... 8 Updated Outline Dimensions... 6 Changes to Ordering Guide... 6 /006 Rev. 0 to Rev. A Change to Thermal Characteristics Section... 4 Changes to Outline Dimensions... 6 Changes to Ordering Guide... 6 0/004 Revision 0: Initial Version Rev. D Page of 6
Data Sheet SPECIFICATIONS VCC =.6 V to 5.5 V; TA = 40 C to +85 C, unless otherwise noted; C, C =.0 µf; C3 =. µf; C4 = 4.7 µf. Table. Parameter Min Typ Max Unit Test Conditions INPUT VOLTAGE, VCC.6 5.5 V SUPPLY, ICC.6 5 ma All four LEDs disabled, VCC = 3.3 V, RSET = 7.08 kω, CTRL =, CRTL = SHUTDOWN 5 µa CHARGE PUMP FREQUENCY.5 MHz CHARGE PUMP MODE THRESHOLDS.5 to 3.33 V to.5 3.36 V Hysteresis 40 mv to.5 4.77 V.5 to 4.8 V Hysteresis 40 mv ISET PIN LED : LED Matching 0.3 % ILED = 0 ma, VFB = 0.4 V ISET Pin Voltage.8 V ILED-to-ISET Ratio 0 ILED-to-ISET Ratio Accuracy ±5% MIN COMPLIANCE ON FBx PIN 0.5 V ISET = 5 ma CHARGE PUMP OUTPUT RESISTANCE. Ω mode 3.5 Ω.5 mode 8.0 Ω mode LED 0 ma PWM 0. 00 khz DIGITAL INPUTS Input High 0.7 VCC V Input Low 0.3 VCC V Input Leakage Current µa CHARGE PUMP POWER EFFICIENCY 88 % CTRL =, CRTL =, VCC = 3.4 V, VFB = 0. V, IFB = 0 ma VOUT RIPPLE 30 mv VCC = 3.6 V, ILED = 0 ma, all four LEDs enabled Guaranteed by design. Not 00% production tested. Rev. D Page 3 of 6
ABSOLUTE MAXIMUM RATINGS TA = 5 C, unless otherwise noted. Table. Parameter Rating Supply Voltage, VCC 0.3 V to +6.0 V ISET 0.3 V to +.0 V CTRL, CTRL 0.3 V to +6.0 V VOUT Shorted Indefinite Feedback Pins FB to FB4 0.3 V to +6.0 V Operating Temperature Range 40 C to +85 C VOUT 80 ma Storage Temperature Range 65 C to +5 C Power Dissipation mw ESD Class Short through LED. Based on long-term current density limitations. Data Sheet Stresses at or above those listed under Absolute Maximum Ratings may cause permanent damage to the product. This is a stress rating only; functional operation of the product at these or any other conditions above those indicated in the operational section of this specification is not implied. Operation beyond the maximum operating conditions for extended periods may affect product reliability. THERMAL CHARACTERISTICS 6-lead LFCSP (CP-6-3) package: θja =50 C/W ESD CAUTION Rev. D Page 4 of 6
Data Sheet PIN CONFIGURATION AND FUNCTION DESCRIPTIONS FB FB FB3 FB4 5 6 7 8 6 5 4 3 C+ C CTRL C+ 3 TOP VIEW (Not to Scale) 4 9 0 CTRL C NOTES. CONNECT THE EXPOSED PADDLE TO. Figure. Pin Configuration Table 3. Pin Function Descriptions Pin No. Mnemonic Description VOUT Charge Pump Output. A. µf capacitor to ground is required on this pin. Connect VOUT to the anodes of all the LEDs. C+ Flying Capacitor Positive Connection. 3 ISET Bias Current Set Input. The current flowing through the RSET resistor, ISET, is gained up by 0 to provide the ILED current. Connect a resistor, RSET, to to set the bias current as VSET/RSET. Note that VSET =.8 V. 4, 9, 0 Device Ground Pins. 5 to 8 FB to FB4 LED to LED4 Cathode Connection and Charge Pump Feedback. The current flowing in these LEDs is 0 times the current flowing through RSET, ISET. When using fewer than four LEDs, this pin can be left unconnected or connected to. C Flying Capacitor Negative Connection. CTRL Digital Input. 3 V CMOS Logic. Used with CTRL to control the shutdown operation of the main and sub LEDs. 3 CTRL Digital Input. 3 V CMOS Logic. Used with CTRL to control the shutdown operation of the main and sub LEDs. 4 C Flying Capacitor Negative Connection. 5 VCC Positive Supply Voltage Input. Connect this pin to a.6 V to 5.5 V supply with a 4.7 µf decoupling capacitor. 6 C+ Flying Capacitor Positive Connection. EP Expose Paddle. Connect the exposed paddle to. 05050-003 Rev. D Page 5 of 6
Data Sheet TYPICAL PERFORMANCE CHARACTERISTICS 35 0.35 LED (ma) 30 5 0 5 LED (ma) 0.30 0.5 0.0 0.5 0.0 40 C +5 C +85 C 0 0.05 5 4.75 6.75 8.75 0.75.75 4.75 R SET (kω) 05050-004 0.00.6 3. 3.6 4. 4.6 5. 5.6 SUPPLY VOLTAGE (V) 05050-007 Figure 3. ILED (ma) vs. RSET Figure 6. ILED (ma) vs. Temperature ( C), Four LEDs Enabled 0.4 35 0. 30 LED (ma) 0.0 0.8 0.6 0.4 0. 0.0 LED (ma) 5 0 5 0 0.08 40 0 40 80 TEMPERATURE ( C) Figure 4. ILED (ma) Variation over Temperature ( C), VCC = 3.6 V 05050-005 5.6 3.0 3.4 3.8 4. 4.6 5.0 5.4 SUPPLY VOLTAGE (V) Figure 7. ILED (ma) vs. Supply Voltage (V) 05050-008 95 0 90 6 85 LED (ma) 8 EFFICIENCY (%) 80 75 70 4 65 0 0 0 40 60 80 00 DUTY CYCLE (%) Figure 5. ILED (ma) vs. PWM Dimming (Varying Duty Cycle), Four LEDs Enabled, Frequency = khz 05050-006 60 0 0 0 30 40 50 60 70 80 DUTY CYCLE (%) 90 00 Figure 8. LED Efficiency vs. Varying Duty Cycle of khz PWM Signal, Four LEDs Enabled, 0 ma/led 05050-009 Rev. D Page 6 of 6
Data Sheet 80 60 40 C +5 C CTRL/ SUPPLY (ma) 40 0 00 +85 C 80 60.6 3.0 3.4 3.8 4. 4.6 SUPPLY VOLTAGE (V) 5.0 5.4 Figure 9. Supply Current vs. Supply Voltage over Temperature, Four LEDs Enabled @ 0 ma/led 05050-00 3 CH.00V B W CH 60mA B W M 0.0 s CH.44mV CH3.00V Figure. Soft Start Showing the Initial In-Rush Current and VOUT Variation, Four LEDs @ 0 ma/led, VCC = 3.6 V 5050-03 05050-0 05050-04 CH 0.0mV B CH 0.0mV B W W M 0.0 s CH.8mV CH 0.0mV B CH 0.0mV B W W M 400ns CH.4mV Figure 0..5 Mode Operating Waveforms Figure 3. Mode Operating Waveforms POWER EFFICIENCY (%) 90 85 80 75 70 65 60 55 50 45 V F = 3.6V V F = 3.V V F = 3.8V V F = 4.0V V F = 4.3V CH 0.0mV B CH 0.0mV B W W M 400ns CH.4mV Figure. Mode Operating Waveforms 5050-0 40.8.9 3.0 3. 3. 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.0 4. 4. (V) Figure 4. Power Efficiency vs. Supply Voltage over Li-Ion Range, Four LEDs @ 0 ma/led 5050-05 Rev. D Page 7 of 6
Data Sheet POWER EFFICIENCY (%) 90 85 80 75 70 65 60 55 50 45 V F = 3.6V V F = 3.V 40.8.9 3.0 3. 3. 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.0 4. 4. (V) V F = 3.8V V F = 4.0V V F = 4.3V Figure 5. Power Efficiency vs. Supply Voltage over Li-Ion Range, Four LEDs @ 5 ma/led 05050-06 CTRL/ : 44.0ms @: 44.4ms CH.00V CH.00mV M 0.0ms CH 4.36mV Figure 6. TPC Delay C FALL 00 s LOW SIGNAL AMPLITUDE 05050-07 Rev. D Page 8 of 6
Data Sheet THEORY OF OPERATION The charge pump driver for LCD white LED backlights implements a multiple-gain charge pump (,.5, ) to maintain the correct voltage on the anodes of the LEDs over a.6 V to 5.5 V (Li-Ion) input supply voltage. The charge pump automatically switches among /.5 / modes, based on the input voltage, to maintain sufficient drive for the LED anodes, with VCC input voltages as low as.6 V. It also includes regulation of the charge pump output voltage for supply voltages up to 5.5 V. The s four LEDs are arranged into two groups, main and sub. The main display can have up to three LEDs (FB to FB3), and the sub display has one LED (FB4) (see Figure 8). The CTRL and CTRL digital input control pins control the shutdown operation and the brightness of the main and sub displays (see Table 4). Table 4. Shutdown Truth Table CTRL CTRL LED Shutdown Operation 0 0 Sub display off/main display off 0 Sub display off/main display on 0 Sub display on/main display off Sub display on/main display on An external resistor, RSET, is connected between the ISET pin and. This resistor sets up a reference current, ISET, which is internally gained up by 0 within the to produce ILED currents of up to 0 ma/led (ILED = ISET 0 and ISET =.8 V/RSET). The uses four separate current sinks to sense each LED current individually with a typical matching performance of 0.3%. This current matching performance ensures uniform brightness across a color display. The lets the user control the brightness of the white LEDs with a digital PWM signal applied to CTRL and/or CTRL. The duty cycle of the applied PWM signal determines the brightness of the main and/or sub display backlight white LEDs. The also allows the brightness of the white LEDs to be controlled using a dc voltage (see Figure 7). Soft start circuitry limits the in-rush current flow at power-up. The is fabricated using CMOS technology for minimal power consumption and is packaged in a 6-lead lead frame chip scale package. V BRIGHT 0V.5V R = 5kΩ R SET = 3.4kΩ 05050-0 Figure 7. PWM Brightness Control Using a DC Voltage Applied to VBRIGHT C µf C µf C4 4.7µF CHARGE PUMP /.5 / MODE C3.µF MAIN SUB CTRL CTRL CONTROL LOGIC V REF OSC FB FB FB3 FB4 R SET LED CONTROL CIRCUIT CONTROL CONTROL CONTROL 3 CONTROL 4 CONTROLLED SINKS 05050-00 Figure 8. Functional Block Diagram Rev. D Page 9 of 6
AUTOMATIC GAIN CONTROL The automatic gain control block controls the operation of the charge pump by selecting the appropriate gain for the charge pump. Doing so maintains sufficient drive for the LED anodes at the highest power efficiency over a.6 V to 5.5 V input supply range. The charge pump switching thresholds are described in Table 5. Table 5. Charge Pump Switching Thresholds Gain Threshold (V).5 to 3.33 to.5 3.36 to.5 4.77.5 to 4.8 BRIGHTNESS CONTROL WITH A DIGITAL PWM SIGNAL PWM brightness control provides the widest brightness control method by pulsing the white LEDs on and off using one or both digital input control pins, CTRL and CTRL. PWM brightness control also removes any chromaticity shifts associated with changing the white LED current, because the LEDs operate at either zero current or full current (set by RSET). The digital PWM signal applied with a frequency of 00 Hz to 00 khz turns the current control sinks on and off using CTRL and/or CTRL. The average current through the LEDs changes with the PWM signal duty cycle. If the PWM frequency is much less than 00 Hz, flicker may be seen in the LEDs. For the, zero duty cycle turns off the LEDs, and a 50% duty cycle results in an average LED current, ILED, that is half the programmed LED current. For example, if RSET is set to program 0 ma/led, a 50% duty cycle results in an average ILED of 0 ma/led, which is half the programmed LED current. Data Sheet Applying a digital PWM signal to one or both digital input control pins, CTRL and CTRL, adjusts the brightness of the sub and/or main displays. The s four white LEDs are organized into two groups, main display (FB to FB3) and sub display (FB4); refer to the Theory of Operation section. The brightness of the s main and sub displays can be controlled together or separately. This is achieved by applying a digital PWM signal to both the CTRL and CTRL pins. The duty cycle of the applied digital PWM signal determines the brightness of the main and sub displays together. Varying the duty cycle of the applied PWM signal varies the brightness of the main and sub displays from 0% to 00%. By holding CTRL low and applying a digital PWM signal to CTRL, the sub display is turned off and the main display is turned on. Then the brightness of the main display is determined by the duty cycle of the applied digital PWM signal. By applying a digital PWM signal to CTRL and holding CTRL low, the sub display is turned on and the main display is turned off. Then the brightness of the sub display is determined by the duty cycle of the applied digital PWM signal. By applying a digital PWM signal to CTRL and holding CTRL high, the sub display is turned on and the main display is turned on. Then the brightness of the sub display is determined by the duty cycle of the applied digital PWM signal. The brightness of the main display is set to the maximum (maximum is set by RSET). By holding CTRL high and applying a digital PWM signal to CTRL, the sub and main displays are turned on. Then the brightness of the main display is determined by the duty cycle of the applied digital PWM signal. The brightness of the sub display is set to the maximum (maximum is set by RSET). 3.4V I IN PWM INPUT OR HIGH/LOW PWM INPUT OR HIGH/LOW R SET CTRL CTRL C µf C µf ADM8845 FB FB FB3 FB4 C3.µF Figure 9. Digital PWM Brightness Control Application Diagram 05050-08 When CTRL and CTRL are low, the LED current control sinks shutdown. Shutdown of the charge pump is delayed by 5 ms. This timeout period, tcp, allows the to determine if a digital PWM signal is present on CTRL and CTRL, or if the user has selected a full chip shutdown (see Figure 0). If digital PWM brightness control of the LEDs is not required, a constant Logic Level (VCC) or Logic Level 0 () must be applied. The four white LED in the are arranged into two groups, sub and main. It is possible to configure the four LEDs as in Table 6. Refer also to Figure 0. Rev. D Page 0 of 6
Data Sheet Table 6. Digital Inputs Truth Table CTRL CTRL LED Operation 0 0 Sub display off/main display off (full shutdown), 0 Sub display off/main display on, 3 0 Sub display on/main display off, Sub display on/main display on (full on), 3 0 PWM Sub display off/digital PWM brightness control on main display 4, 5 PWM 0 Digital PWM brightness control on sub display/main display off, 4 PWM Sub display on/digital PWM brightness control on main display, 5 PWM Digital PWM brightness control on sub display/main display on 5 PWM PWM Digital PWM brightness control on sub and main display 5 Sub display on means the display is on with the maximum brightness set by the RSET resistor. CTRL = means a constant logic level (VCC) is applied to CTRL. Main display off means only the main display is off. CTRL = 0 means a constant logic level () is applied to CTRL. 3 Main display on means the display is on with the maximum brightness set by the RSET resistor. CTRL = means a constant logic level (VCC) is applied to CTRL. 4 Sub display off means only the sub display LEDs is off. CTRL = 0 means a constant logic level () is applied to CTRL. 5 PWM means a digital PWM signal is applied to the CTRL and/or the CTRL pin with a frequency from 00 Hz to 00 khz. LED CONFIG. FULL ON SUB AND MAIN 50% DUTY CYCLE MAIN AND SUB OFF MAIN 80% DUTY CYCLE, SUB OFF t CP CTRL CTRL I LED (SUB) I LED (MAIN) 00% SUB DISPLAY BRIGHTNESS 50% 00% SHDN MAIN DISPLAY BRIGHTNESS 50% 80% SHDN 37ms > t CP > 5ms 05050-00 Figure 0. Application Timing Rev. D Page of 6
LED BRIGHTNESS CONTROL USING A PWM SIGNAL APPLIED TO V PWM Adding two external resistors and a capacitor, as shown in Figure, can also be used for PWM brightness control. This PWM brightness control method can be used instead of CTRL and/or CTRL digital PWM brightness control. With this configuration, CTRL and CTRL digital logic pins can control shutdown of the white LEDs, and VPWM can control the brightness of all the white LEDs. This is done by applying a high frequency PWM signal (amplitude 0 V to.5 V) to drive an R-C-R filter on the ISET pin of the. A 0% PWM duty cycle corresponds to 0 ma/led, and a 00% PWM duty cycle corresponds to a 0 ma/led. At PWM frequencies above 5 khz, C5 may be reduced (see Figure ). The amplitude of the PWM signal must only be 0 V and.5 V to result in 0 ma flowing in each LED. I LED I _ Voltage ( Duty Cycle) SET = 0 RSET R 00 R + R SET 00% = I LED = 0mA 0% = I LED = 0mA Data Sheet LED BRIGHTNESS CONTROL USING A DC VOLTAGE APPLIED TO V BRIGHT By adding one resistor, as shown in Figure 7, this configuration can also be used for brightness control of the white LEDs by using a dc voltage applied to the VBRIGHT node. Figure shows an application example of LED brightness control using a dc voltage with an amplitude of 0 V to.5 V applied to VBRIGHT. The equation for ILED is ISET = [(/RSET + /R)(VSET)] [(/R)(VBRIGHT)] ILED = 0 ISET where: R = 5 kω VSET = voltage at ISET pin (.8 V) V BRIGHT I LED.5V 0mA.6V 7.mA 0.8V 3.6mA 0V 0mA Figure. PWM Brightness Control Application Diagram Using a DC Voltage Applied to VBRIGHT 05050-03 V PWM 0V.5V R = 7.5kΩ R = 7.5kΩ C5 = µf R SET = 3.4kΩ Figure. PWM Brightness Control Using Filter-PWM Signal 05050-0 Rev. D Page of 6
Data Sheet APPLICATIONS LAYOUT CONSIDERATIONS AND NOISE Because of the s switching behavior, PCB trace layout is an important consideration. To ensure optimum performance, a ground plane should be used, and all capacitors (C, C, C3, C4) must be located with minimal track lengths to the pins of the. WHITE LED SHORTING If an LED is shorted, the continues to drive the remaining LEDs with ILED per LED (ILED = ISET 0 ma). This is because the uses four internal current sinks to produce the LED current. If an LED is shorted, the continues to sink (ISET 0 ma). DRIVING FOUR LEDS IN THE MAIN DISPLAY ONLY The can be operated with four LEDs in the main display only (see Figure 3). With this configuration, CTRL and CTRL are used together to control the main display shutdown operation and brightness control. DRIVING FEWER THAN FOUR LEDS The can be operated with fewer than four LEDs in parallel by simply leaving the unused FBx pins floating or by connecting them to. For example, Figure 4 shows three LEDs being powered by the. LCD MAIN DISPLAY.6V 5.5V.6V 5.5V CTRL CTRL FB FB FB3 FB4 CTRL CTRL FB FB FB3 FB4 R SET 05050-04 R SET 05050-05 Figure 3. Driving Four White LEDs Figure 4. Driving Three White LEDs MAIN DISPLAY SUB DISPLAY.6V 5.5V CTRL CTRL FB FB FB3 FB4 R SET Figure 5. Typical Application Diagram 05050-00 Rev. D Page 3 of 6
Data Sheet USING SMALLER CAPACITOR VALUES The can be operated with the smaller capacitor values described here to reduce capacitor footprint sizes. Option Input and output ripple plots for and.5 modes of operation are shown with C, C = 0. μf; C3 = 0.47 μf; and C4 = μf. Option Input and output ripple plots for and.5 modes of operation are shown with C, C = 0. μf; C3 = 0.47 μf; and C4 = 4.7 μf. 3 3 CH3 0.0mV B W CH 0.0mV B W M 400ns CH3 33mV 05050-06 CH3 0.0mV CH 0.0mV B W B W M.00 s CH3 33mV 05050-08 Figure 6. Mode Operation, Four LEDs with 0 ma/led at VCC = 5.0 V, with a μf VCC Decoupling Capacitor Figure 8. Mode Operation, Four LEDs with 0 ma/led at VCC = 5.0 V, with a 4.7 μf VCC Decoupling Capacitor 3 3 CH 0.0mV B W M 400ns CH3 33mV CH3 50.0mV B W Figure 7..5 Mode Operation, Four LEDs with 0 ma/led at VCC = 3.6 V, with a μf VCC Decoupling Capacitor 05050-07 CH3 50.0mV CH 0.0mV B W B W M 400ns CH3 33mV Figure 9..5 Mode Operation, Four LEDs with 0 ma/led at VCC = 3.6 V, with a 4.7 μf VCC Decoupling Capacitor 05050-09 Rev. D Page 4 of 6
Data Sheet POWER EFFICIENCY The power efficiency (η) equations are as follows: where: η = POUT/PIN PIN = ((VCC ILOAD Gain) + (IQ VCC)) POUT = 4 (VF ILED) IQ is the quiescent current of the,.6 ma. VF is the LED forward voltage. Gain is the charge pump mode (,.5, ). Example The driving four white LED with 0 ma/led at VCC = 3.4 V (.5 mode), LED VF = 4.5 V. PIN = ((VCC ILOAD Gain) + (VCC IQ)) PIN = ((3.4 80 ma.5) + (3.4.6 ma)) PIN = ((0.408) + (0.00884)) PIN = 0.4684 POUT = 4(VF ILED) POUT = 4(4.5 V 0 ma) POUT = 0.36 Example The driving four white LED with 0 ma/led at VCC = 3.4 (.5 mode), LED VF = 3.6 V. PIN = ((VCC ILOAD Gain) + (VCC IQ)) PIN = ((3.4 80 ma.5) + (3.4.6 ma)) PIN = ((0.408) + (0.00884)) PIN = 0.4684 POUT = 4(VF ILED) POUT = 4(3.6 V 0 ma) POUT = 0.88 η = POUT/PIN η = 0.88/0.4684 η = 70 % η = POUT/PIN η = 0.36/0.4684 η = 87 % = 3.4V I IN I LOAD R SET 7.3kΩ CTRL CTRL FB FB FB3 FB4 Figure 30. Charge Pump Power Efficiency Diagram, Example 05050-09 Rev. D Page 5 of 6
Data Sheet OUTLINE DIMENSIONS PIN INDICATOR 3.0 3.00 SQ.90 0.50 BSC 0.30 0.3 0.8 3 6 DETAIL A (JEDEC 95) PIN INDICATOR AREA OPTIONS (SEE DETAIL A) EXPOSED PAD.75.60 SQ.45 9 4 PKG-00538 0.80 0.75 0.70 SEATING PLANE TOP VIEW TOP VIEW 0.50 0.40 0.30 0.05 MAX 0.0 NOM COPLANARITY 0.08 0.0 REF 8 5 BOTTOM VIEW COMPLIANT TOJEDEC STANDARDS MO-0-WEED-6. Figure 3. 6-Lead Lead Frame Chip Scale Package [LFCSP] 3 mm 3 mm Body and 0.75 mm Package Height (CP-6-) Dimensions shown in millimeters 0.0 MIN FOR PROPER CONNECTION OF THE EXPOSED PAD, REFER TO THE PIN CONFIGURATION AND FUNCTION DESCRIPTIONS SECTION OF THIS DATA SHEET. 0-3-07-E ORDERING GUIDE Model Temperature Range Package Description Package Option Branding ACPZ-REEL7 40 C to +85 C 6-Lead Lead Frame Chip Scale Package [LFCSP] CP-6- MU EB-EVALZ Evaluation Board Z = RoHS Compliant Part. 004 07 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D05050-0-3/7(D) Rev. D Page 6 of 6