ADP5501 Analog Devices, ADP5501 Datasheet
ADP5501
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ADP5501 Summary of contents
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... INT 15 RST NC The ADP5501 can detect ambient light levels and adjust the backlight brightness accordingly, resulting in extended battery life. Once configured, the ADP5501 is capable of controlling the display backlight intensity, on/off timing, dimming, and fading 2 C®- without the intervention of the main processor, which translates into valuable battery power savings ...
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... ADP5501 TABLE OF CONTENTS Features .............................................................................................. 1 Applications ....................................................................................... 1 Typical Operating Circuit ................................................................ 1 General Description ......................................................................... 1 Revision History ............................................................................... 2 Specifications ..................................................................................... 3 Absolute Maximum Ratings ............................................................ 5 Thermal Resistance ...................................................................... 5 ESD Caution .................................................................................. 5 Pin Configuration and Function Descriptions ............................. 6 Typical Performance Characteristics ............................................. 7 Theory of Operation ........................................................................ 9 Backlight Drive Control .............................................................. 9 Backlight Operating Levels ....................................................... 10 Backlight Maximum and Dim Settings ................................... 10 Backlight Turn-On/Turn-Off/Dim ...
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... V ≤ VDDIO ≤ 3.3 V OH-LEAKAGE LED Sink disabled LEAKAGE LED Applied pin voltage = 1 V FULLSCALE TS T rising falling HYS J f SCL t HIGH t LOW t SU, DAT t HD, DAT t SU, STA Rev Page ADP5501 Min Typ Max Unit 2.7 5 1.8 3.3 V 1.7 2.1 V 2.4 2.7 V 1.1 1.3 V 1.4 V 0.1 1 μA 0.1 1 μ μ ...
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... ADP5501 Parameter Hold Time for Start/Repeated Start Bus Free Time for Stop and Start Condition Setup Time for Stop Condition Rise Time for SCL and SDA Fall Time for SCL and SDA Pulse Width of Suppressed Spike Capacitive Load for Each Bus Line 1 All limits at temperature extremes are guaranteed via correlation using standard statistical quality control (SQC) ...
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... Table 3. Thermal Resistance –0 +0 Package Type −40°C to +85°C –40°C to +125°C 24-Lead LFCSP_VQ –65°C to +150°C JEDEC J-STD-020 ESD CAUTION ), using the following JA Rev Page ADP5501 θ Unit JA 50 ⁰C/W ...
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... Overvoltage Monitor Input for the Boost Converter. 23 BL_SNK Backlight Current Sink. 24 GND Ground. EPAD The exposed pad must be connected to ground. PIN 1 PGND 1 INDICATOR 18 GND CMP_IN ADP5501 3 16 VDDIO INT SDA 4 15 RST TOP VIEW SCL 5 (Not to Scale) 14 LED0 LED2 NOTES CONNECT. ...
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... Figure 7. Standby Supply Current vs. VBAT 0.5 Figure 8. Typical Auxiliary LED Pin (LED0, LED1, LED2), Full-Scale Sink Current vs. Applied Pin Voltage 30 Rev Page ADP5501 TEMP = –40°C TEMP = +85°C 3.5 4.0 4.5 5.0 5.5 6.0 VBAT (V) 1.0 1.5 2.0 2.5 3.0 AUX LED PIN VOLTAGE (V) ...
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... ADP5501 SW 1 INDUCTOR CURRENT 2 BST BL_SNK 3 4 CH1 20.0V CH2 500mA TIME (4µs/DIV) CH3 10.0V CH4 1.0V Figure 9. Boost Operation (Backlight = 30 mA INDUCTOR CURRENT 2 BST BL_SNK 3 4 CH1 20.0V CH2 500mA TIME (4µs/DIV) CH3 10.0V CH4 1.0V Figure 10. Boost Operation (Backlight = 15 mA INDUCTOR CURRENT ...
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... Programmable fading is also available for the three LED sinks. 2 Once programmed through its I C-compatible interface, the ADP5501 can run autonomously. An interrupt line ( INT ) is available to alert an external microprocessor of the status of its ambient light sensor comparator states, current limit, thermal overload, and overvoltage conditions. ...
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... The BL_LAW bits, in Register 0x02, are used to swap between algorithms. By default, the ADP5501 uses a linear algorithm (BL_LAW = 00), where the backlight current increases linearly for a corresponding increase of input code. Backlight current, in milliamperes (mA), is determined by the following equation: Backlight Current = Code × ...
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... BL_EN = 0 LINEAR BACKLIGHT FADE-IN AND FADE-OUT To counteract the abrupt effect on the eyes of near instant turn- on and turn-off of the backlight, the ADP5501 contains timers to facilitate smooth fading among the off, on, and dim states. By default (BL_LAW = 00 in Register 0x02), the ADP5501 implements a fading scheme using the linear backlight code algorithm (see Equation 1) ...
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... ADP5501 The BL_FI timer in Register 0x04 can be used for smooth fade- in transitions from low to high backlight settings such as off to dim, off to maximum, and dim to maximum. The BL_FI timer can be programmed to one of 15 settings ranging from 0.3 sec to 5.5 sec. The BL_FI timer should be programmed before asserting BL_EN ...
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... FADE-OUT TIME (Sec) Figure 28. Square Law Fade-Out Times BST BL_VALUE MUX COUNTERS AND BL_OFFT CONTROL LOGIC BL_DIMT BL_LVL BL_FI BL_FO Figure 29. Backlight Brightness Control (Cubic) ADP5501 0.3 SEC 0.6 SEC 0.9 SEC 1.2 SEC 1.5 SEC 1.8 SEC 2.1 SEC 2.4 SEC 2.7 SEC 3.0 SEC 3.5 SEC 4.0 SEC 4.5 SEC 5.0 SEC 5.5 SEC 4 ...
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... UNIT FADE TIME Figure 30. Fade Law Comparison over a Unit Fade Time AMBIENT LIGHT SENSING The ADP5501 can be used in conjunction with an external photosensor to detect when ambient light conditions drop below programmable set points. An ADC samples the output of the external photosensor. The ADC result is fed into two pro- grammable trip comparators. The ADC has an input range of 0 μ ...
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... These LEDx_CURRENT registers are six bits wide, allowing the user to set the LED sink current to one of 64 different levels between 0 mA and 14 mA. The ADP5501 can implement two distinct algorithms to achieve a linear and a nonlinear relation- ship between input code and sink current. ...
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... Fade-out times represent the time it takes to fade from mA. Fading between intermediate settings is shorter. The fade timers should be programmed before asserting LEDx_EN in Register 0x11. By default (LED_LAW = 0 in Register 0x11), the ADP5501 implements a fading scheme using the linear algorithm (see Equation 3). 15 ...
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... FADE-OUT OVERVOLTAGE INTERRUPT OFF RESET INPUT (RST) TIME The ADP5501 can be restored to a power-on reset state if the RST pin is held low. RST contains a debounce circuit; therefore, the pin must be held low for greater than 75 μs (typical) before a reset occurs. . Rev Page ...
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... The cycle continues with a repeat start, followed by the chip read address (0x65). 6. The ADP5501 acknowledges the chip read address byte by pulling the data line low. 7. The ADP5501 places the contents of the previously addressed register on the bus for readback. ...
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... Contains the on and off timers for the status LED current sinks. 0x13 LED_FADE Contains the fade-in and fade-out timers for the status LED current sinks. 0x14 LED0_CURRENT Sets the LED0 sink current. 0x15 LED1_CURRENT Sets the LED1 sink current. 0x16 LED2_CURRENT Sets the LED2 sink current. Rev Page ADP5501 ...
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... ADP5501 DETAILED REGISTER DESCRIPTIONS Table 7. Register 0x00, Device Mode and Status (MODE_STATUS) Bit Name R/W Description 7 STNBY R the device is in standby mode. (If 1.8V ≤ VDDIO ≤ 2.7V, then the device is in operating mode. Additional functions such as backlight driver, LED sinks, and ambient light sensor functions can be enabled. ...
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... Rev Page ADP5501 ...
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... ADP5501 Table 11. Register 0x04, Backlight Fade-In and Fade-Out Timers (BL_FADE) Bit Name R/W Description BL_FO R/W Backlight fade-out timer; the timer should be set before BL_EN is set. 0000 = the timer is disabled. 0001 = 0.3 sec. 0010 = 0.6 sec. 0011 = 0.9 sec. 0100 = 1.2 sec. 0101 = 1.5 sec. 0110 = 1.8 sec. ...
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... Comparator L2_CMPR. If automatic backlight adjustment is required, BL_AUTO_ADJ must be set also. Description Sets the trip value for Comparator L2_CMPR. If ambient light levels fall below this trip point, L2_OUT is set. Each code is equal to 4 μA (typical). Full scale is 1000 μA (typical). Rev Page ADP5501 ...
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... ADP5501 Table 21. Register 0x0E, Level 2 (Office) Comparator Hysteresis (L2_HYS) Bit Name R/W Description L2_HYS R/W Sets the hysteresis value for Comparator L2_CMPR. If ambient light levels increase above L2_TRIP + L2_HYS, L2_OUT is cleared. Each code is equal to 4 μA (typical). Full scale is 1000 μA (typical). ...
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... See Figure 33 for LED sink current vs. code relationship. Description Sink current setting for LED1. See Figure 33 for LED sink current vs. code relationship. Description Sink current setting for LED2. See Figure 33 for the LED sink current vs. code relationship. Rev Page ADP5501 ...
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... ADP5501, damage to the device can occur. The ADP5501 boost converter has an OVP limit (typical). The ADP5501 also has a feature that ramps down the backlight code when an OVP condition is detected. This may be useful in conditions where LEDs with marginally high forward voltages are used in low ambient conditions ...
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... Component Selection The ADP5501 boost converter is designed for use with a 4.7 μH inductor. Choose an inductor with a sufficient current rating to prevent it from going into saturation. The peak current limit of the ADP5501 is 750 mA (maximum), so choose an inductor with a greater saturation rating. To maximize efficiency, choose an inductor with a low series resistance (DCR). ...
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... PIN 1 INDICATOR 1.00 12° MAX 0.85 0.80 SEATING PLANE ORDERING GUIDE Model Temperature Range 1 ADP5501ACPZ-RL −40°C to +85° RoHS Compliant Part. ©2008 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 4.00 BSC SQ 0.60 MAX 0.50 BSC TOP 3 ...