BD1206GUL

LED Drivers for LCD Backlights Backlight LED Driver for Small LCD Panels (Charge Pump Type) BD1206GUL No.10040EAT08 ●Description BD1206GUL is 5ch or 6ch parallel LED driver for the portable instruments. This IC is equipped with an automatic transition charge pump and 16-step LED drivers. Hence this IC realizes high efficiency and high accuracy drive of LEDs. Additionally, this IC can synchronize LED drive with external PWM signal. This IC is best suited to turn on white LEDs that require high-accuracy LED brightness control. ●Features 1) 5ch or 6ch parallel LED driver is mounted 2) 16-step LED current adjust function 3) LED current matching is 5% or less 4) Driving control via a single-line digital control interface 5) Automatic transition charge pump type DC/DC converter (×1, ×1.5, ×2) 6) High efficiency achieved (Maximum over 93%) 7) It transits for the most suitable power operating by the LED terminal process of the 6th light when only 5 lights driving 8) Various protection functions such as output voltage protection and thermal shutdown circuit are mounted. 9) The input external PWM is possible and the back light control interlocked with the motion picture is possible. 10) Package: VCSP50L2 (Thick 0.55mm MAX, Pin pitch 0.5mm) CSP15pin package ●Absolute Maximum Ratings (Ta=25ºC) Parameter Power supply voltage Input voltage ( EN , PWMIN ) Power dissipation Operating temperature range Storage temperature range (Note) Symbol VMAX Vdin Pd Topr Tstg Ratings 7 GND-0.3 ~ VBAT+0.3 900 -30 ~ +85 -55 ~ +150 Unit V V mW ºC ºC Power dissipation deleting is 7.2mW/ ºC, when it’s used in over 25 ºC.(It’s deleting is on the board that is ROHM’s standard) Dissipation by LSI should not exceed tolerance level of Pd. o ●Operating Conditions (Ta = -30 ~ 85 C) Parameter Operating power supply voltage Symbol VBAT Limits 2.7 ~ 5.5 Unit V *This chip is not designed to protect itself against radioactive rays. *This material may be changed on its way to designing. *This material is not the official specification. www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 1/12 2010.02 - Rev.A BD1206GUL ●Electrical Characteristics (Unless otherwise noted, Ta = +25oC, VBAT=3.6V) Limits Parameter Symbol Units Min. Typ. Max. Current Consumption Quiescent Current Current Consumption1 Current Consumption2 Charge Pump Oscillator frequency Current Source LED maximum current LED current accuracy LED current matching LED control voltage Logic control terminal Low threshold voltage High threshold voltage High level Input current Low level Input current Minimum EN High time Minimum EN Low time EN Off Timeout Latch time Access available time VIL VIH IIH IIL THI TLO TOFF TLAT Tacc 1.4 -1 0.05 0.3 1 1 1 0 0 0.4 1 100 100 5 V V μA μA μs μs ms ms ms EN, PWMIN EN, PWMIN ILED-max ILED-diff ILED-match VLED 18 20 0.5 0.15 22 10.0 5.0 0.25 mA % % V VBAT≥3.2V fOSC 0.56 0.85 1.14 MHz Iq Idd1 Idd2 0.1 62 123 1 64 126 μA mA mA EN=0V Technical Note Condition x 1.0 Mode Include LED current (60mA) x 2.0 Mode Include LED current (60mA) LED current setting is 10.0mA, LED terminal voltage is 1.0V LED current setting is 10.0mA, LED terminal voltage is 1.0V Minimum voltage from LED1 to LED6 pins EN = VBAT, PWMIN = VBAT EN = 0V, PWMIN = 0V Described in Fig.5 Described in Fig.5 Described in Fig.5 Described in Fig.5 Described in Fig.5 www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 2/12 2010.02 - Rev.A BD1206GUL ●Block Diagram C1N C1P C2N C2P Technical Note VBAT ×1, ×1.5, ×2 Charge pump Over Voltage Protect Charge Pump Mode Control VOUT EN Enable/ Brightness Control OSC Vout Control TSD LED1 LED2 LED3 LED4 LED5 PWMIN 4 LED6 DET LED6 Current DAC GND Pin number 14pin Fig. 1 Block Diagram ●Pin Configuration [Bottom View] D LED1 LED2 PWMIN VBAT C LED3 LED4 index EN C1N B LED5 C2N C1P A LED6 GND VOUT C2P 1 2 3 4 Fig. 2 Pin Configuration www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 3/12 2010.02 - Rev.A BD1206GUL ●Package Outline Technical Note 1 206 Lot No. ( UNIT : mm ) Fig. 3 Package Dimension www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 4/12 2010.02 - Rev.A BD1206GUL ●Pin Descriptions Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Terminal No. D4 B4 C4 A4 B3 A3 C3 D1 D2 C1 C2 B1 A1 D3 A2 Pin Name VBAT C1P C1N C2P C2N VOUT EN LED1 LED2 LED3 LED4 LED5 LED6 PWMIN GND In/Out In/Out In/Out In/Out In/Out Out In Out Out Out Out Out Out In Type A A B A B A C B B B B B A C D Power supply Function Technical Note Flying capacitor pin positive (+) side Flying capacitor pin negative (-) side Flying capacitor pin positive (+) side Flying capacitor pin negative (-) side Charge pump output ON/OFF and dimming control LED current driver output 1 LED current driver output 2 LED current driver output 3 LED current driver output 4 LED current driver output 5 LED current driver output 6 PWM Control GND ●Pin ESD Type Type A Type B VBAT Type C VBAT PAD GND PAD GND PAD GND Type D VBAT PAD Fig. 4 Pin ESD Type www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 5/12 2010.02 - Rev.A BD1206GUL Technical Note ●Separate Function Description (1) LED driver a) Register access control protocol LED current is controlled by only EN terminal. It is possible to access the register inside of this chip by using the protocol below. Accessing the registers with using this protocol operates LED driver ON/OFF and selecting the mode. Moreover, MAX current can be outputted without Clock input to EN terminal by holding H zone of fixed time after EN terminal starting. < When setting current level > Tacc Tpulse TLO THI TLAT TOFF EN 1 2 n-1 n (N≦16) LED Current Setting 0 (Notes) TaccMIN < Tpulse < n TaccMAX Please input a pulse on this condition 0 < When starting by MAX setup > TaccMAX TOFF EN LED Current Setting 0 １ 0 Fig.5 Register access protocol Tacc TLAT TLAT TLAT TLAT EN 16pulse 15pulse 14pulse 13pulse 1mA 0.5mA LED Current O FF 0.125mA 0.25mA Fig.6 Slope control example (Note) ・In the case of N > 16, BD1206GUL selects the mode of N = 16. ・LED current is changed by the pulse of EN pin. Be careful to noise of EN signal. ・Reset BD1206GUL when the set is unusual. (Keep EN=L over Toff time.) www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 6/12 2010.02 - Rev.A BD1206GUL Technical Note b) LED current level The interface records rising edges of the EN pin and decodes them into 16 different indicated in following table. Data 1 2 3 4 5 6 7 8 Output current [mA] 20.0 17.0 14.0 12.0 10.0 8.5 7.0 6.0 Data 9 10 11 12 13 14 15 16 Output current [mA] 5.0 4.0 3.0 2.0 1.0 0.5 0.25 0.125 (2) Charge pump a) Description of operations Pin voltage comparison takes place at Vout control section, and then Vout generation takes place so that the LED cathode voltage with the highest Vf is set to 0.15V. A boost rate is changed automatically to a proper one at the Charge Pump Mode Control section so that operation can take place at possible low boost rate. In addition, when the VOUT output is short-circuited to GND, the leak current is suppressed via the over current protection function. b) Soft start function BD1206GUL have a soft start function that prevents the rush current. TOFF EN/LED* VOUT ILED Soft Start Ordinal mode * EN/LED is an internal enable Fig.7 Soft Start c) Automatic boost rate change The boost rate automatically switches to the best mode. * (×1 mode  ×1.5 mode) or (×1.5 mode  ×2 mode) If a battery voltage drop occurs BD1206GUL cannot maintain the LED constant current, and then mode transition begins. * (×1.5 mode  ×1 mode) or (×2 mode  ×1.5 mode) If a battery voltage rise occurs, VOUT and VBAT detection are activated, and then mode transition begins. (3) UVLO (Under Voltage Lock Out) If the input voltage falls below 2.2V(Typ.), BD1206GUL is shut down to prevent malfunction due to ultra-low voltage. (4) OVP (Over Voltage Protection) This circuit protects this IC against damage when the C/P output voltage (VOUT) rises extremely for some external factors. (5) Thermal shutdown (TSD) To protect this IC against thermal damage or heat-driven uncontrolled operations, this circuit turns off the output if the chip temperature rises over 175ºC. In addition, it turns on the output if the temperature returns to the normal temperature. Because the built-in thermal protection circuit is intended to protect the IC itself, the thermal shutdown detection temperature must be set to below 175ºC in thermal design. www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 7/12 2010.02 - Rev.A BD1206GUL (6) Power sequence EN signal must be released after VBAT voltage enough rise up. Prohibit the VBAT rise up during EN=”H”. Technical Note VBAT EN Fig.8 Power sequence (7) PWM control PWM control by the external terminal (PWMIN) is possible. It becomes PWM operation, which used LED current by a register setup as the base and is the best for the brightness compensation by external control.If the application with is not use PWM, PWMIN pin must be short to VBAT. E N /L E D * I n te rn a l S o ft-S ta rt T im e VOUT N o n -P W M P W M IN in p u t L E D C u rre n t P W M IN in p u t PWMIN L H LED Current Compulsion OFF Normal operation L E D C u rre n t Fig.9 External PWM input solution It is possible to make it a PWMIN input before EN/LED* is “H”. A PWM drive becomes effective after the time of LED current standup. When rising during PWM operation, as for the standup time of VOUT, only the rate of PWM Duty becomes late. Appearance may be influenced when extremely late frequency and extremely low Duty are inputted. Please secure over 120 μs “H” sections at the time of PWM pulse Force. EN/LED* is an internal enable signal www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 8/12 2010.02 - Rev.A BD1206GUL ●Application Circuit Example (6 light with PWM) C1=1μF C1N C1P C2N C2=1μF C2P Technical Note Battery VBAT Cin =1μF ×1, ×1.5, ×2 Charge pump Over Voltage Protect Charge Pump Mode Control VOUT Cout =1μF EN From CPU PWMIN From LCM OSC Enable/ Brightness Control Vout Control TSD LED1 LED2 LED3 LED4 LED5 4 LED6 DET LED6 Current DAC GND Fig.10 Application Circuit Example 1 ●Application Circuit Example (5 light with PWM) C1=1μF C1N C1P C2N C2=1μF C2P Battery VBAT Cin =1μF ×1, ×1.5, ×2 Charge pump Over Voltage Protect Charge Pump Mode Control VOUT Cout =1μF EN From CPU PWMIN From LCM OSC Enable/ Brightness Control Vout Control TSD LED1 LED2 LED3 LED4 LED5 4 LED6DET LED6 Current DAC GND Fig.11 Application Circuit Example 2 www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 9/12 2010.02 - Rev.A BD1206GUL ●Application Circuit Example (6 light without PWM) C1=1μF C1N C1P C2N C2=1μF C2P Technical Note Battery VBAT Cin =1μF ×1, ×1.5, ×2 Charge pump Over Voltage Protect Charge Pump Mode Control VOUT Cout =1μF EN From CPU Battery PWMIN OSC Enable/ Brightness Control Vout Control TSD LED1 LED2 LED3 LED4 LED5 LED6 DET 4 LED6 Current DAC GND Fig.12 Application Circuit Example 3 www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 10/12 2010.02 - Rev.A BD1206GUL Technical Note ●Notes for use (1) Absolute Maximum Ratings An excess in the absolute maximum ratings, such as supply voltage, temperature range of operating conditions, etc., can break down devices, thus making impossible to identify breaking mode such as a short circuit or an open circuit. If any special mode exceeding the absolute maximum ratings is assumed, consideration should be given to take physical safety measures including the use of fuses, etc. (2) Power supply and ground line Design PCB pattern to provide low impedance for the wiring between the power supply and the ground lines. Pay attention to the interference by common impedance of layout pattern when there are plural power supplies and ground lines. Especially, when there are ground pattern for small signal and ground pattern for large current included the external circuits, please separate each ground pattern. Furthermore, for all power supply pins to ICs, mount a capacitor between the power supply and the ground pin. At the same time, in order to use a capacitor, thoroughly check to be sure the characteristics of the capacitor to be used present no problem including the occurrence of capacity dropout at a low temperature, thus determining the constant. (3) Ground voltage Make setting of the potential of the ground pin so that it will be maintained at the minimum in any operating state. Furthermore, check to be sure no pins are at a potential lower than the ground voltage including an actual electric transient. (4) Short circuit between pins and erroneous mounting In order to mount ICs on a set PCB, pay thorough attention to the direction and offset of the ICs. Erroneous mounting can break down the ICs. Furthermore, if a short circuit occurs due to foreign matters entering between pins or between the pin and the power supply or the ground pin, the ICs can break down. (5)Operation in strong electromagnetic field Be noted that using ICs in the strong electromagnetic field can malfunction them. (6)Input pins In terms of the construction of IC, parasitic elements are inevitably formed in relation to potential. The operation of the parasitic element can cause interference with circuit operation, thus resulting in a malfunction and then breakdown of the input pin. Therefore, pay thorough attention not to handle the input pins, such as to apply to the input pins a voltage lower than the ground respectively, so that any parasitic element will operate. Furthermore, do not apply a voltage to the input pins when no power supply voltage is applied to the IC. In addition, even if the power supply voltage is applied, apply to the input pins a voltage lower than the power supply voltage or within the guaranteed value of electrical characteristics. (7) External capacitor In order to use a ceramic capacitor as the external capacitor, determine the constant with consideration given to a degradation in the nominal capacitance due to DC bias and changes in the capacitance due to temperature, etc. (8)Thermal shutdown circuit This LSI builds in a thermal shutdown circuit. When junction temperatures become detection temperature or higher, the thermal shutdown circuit operates and turns a switch OFF. The thermal shutdown circuit, which is aimed at isolating the LSI from thermal runaway as much as possible, is not aimed at the protection or guarantee of the LSI. Therefore, do not continuously use the LSI with this circuit operating or use the LSI assuming its operation. (9) Thermal design Perform thermal design in which there are adequate margins by taking into account the permissible dissipation (Pd)in actual states of use. (10) About the pin for the test, the un-use pin Prevent a problem from being in the pin for the test and the un-use pin under the state of actual use. Please refer to a function manual and an application notebook. And, as for the pin that doesn't specially have an explanation, ask our company person in charge. (11) About the rush current For ICs with more than one power supply, it is possible that rush current may flow instantaneously due to the internal powering sequence and delays. Therefore, give special consideration to power coupling capacitance, power wiring, width of ground wiring, and routing of wiring. (12) About this document This document is the design materials to design a set. So, the contents of the materials aren't always guaranteed. Please design application by having fully examination and evaluation include the external elements. www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 11/12 2010.02 - Rev.A BD1206GUL ●Ordering part number Technical Note B D 1 Part No. 2 0 6 G U L - E 2 Part No. Package GUL: VCSP50L2 Packaging and forming specification E2: Embossed tape and reel VCSP50L2(BD1206GUL) 1PIN MARK Tape 2.00±0.05 Embossed carrier tape (heat sealing method) 3000pcs E2 The direction is the 1pin of product is at the upper left when you hold Quantity 0.55MAX 0.1±0.05 2.00±0.05 15- φ 0.25± 0.05 0.05 A B 0.06 S A (φ0.15)INDEX POST D C B A Direction of feed S ( reel on the left hand and you pull out the tape on the right hand ) B P=0.5×3 0.25±0.05 0.25±0.05 1 P=0.5×3 2 3 4 1pin (Unit : mm) Reel Direction of feed ∗ Order quantity needs to be multiple of the minimum quantity. www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 12/12 2010.02 - Rev.A Notice Notes No copying or reproduction of this document, in part or in whole, is permitted without the consent of ROHM Co.,Ltd. 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