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1 Designated client product This product will be discontinued its production in the near term. And it is provided for customers currently in use only, with a time limit. t can not be available for your new project. Please select other new or existing products. For more information, please contact our sales office in your region. New Japan Radio Co.,Ltd.

2 LOW POWER SWTCHNG REGULATOR GENERAL DESCRPTON The is the industry's first monolithic low power switching regulators available in an 8-lead mini-dp, and designed specifically for battery operated instruments. They each contain a 1.3 temperature compensated bandgap reference, adjustable free running oscillator, voltage comparator, low battery detection circuitry, and a 200mA switch transistor with all of the functions required to make a complete low power switching regulator. These regulators can achieve up to 80% efficiency in most applications while being able to operate over a wide input supply voltage range, 2.6 to 24 at a very low quiescent drain of 280µA. The can be used as a building block in three basic applications : step-up, step-down and inverting. PACKAGE LNE D M FEATURES Operating oltage (2.6 to 24.0 Low Operating Current nternal Low oltage Detect Circuit Pulse Width Modulation Control Circuit Package Outline DP8, DMP8 Bipolar Technology BLOCK DAGRAM D M er

3 ABSOLUTE MAXMUM RATNGS (Ta = 25ºC PARAMETER SYMBOL RATNGS UNT Supply oltage + 24 Power Dissipation P D (DP8 500 (DMP8 300 mw mw Operating Temperature Range T opr -40 to + 85 ºC Storage Temperature Range T stg -40 to +125 ºC ELECTRCAL CHARACTERSTCS DC Electrical Characteristics (+ = 6, Ta = 25ºC PARAMETER SYMBOL TEST CONDTON MN. TYP. MAX. UNT Operating Current (1 CC ( µa Operating Current (2 CC (2 + = µa Reference oltage REF Sw. Saturation oltage SW SW = 100mA Sw. Current SW SW = ma Sw. Leakage Current SWO 3 PN = µa Operating Frequency F O C X = 50pF khz Low Battery Output Current LED (L 1 PN = 1.1, 8 PN = µa Low Battery Output Leakage Current LED (H 1 PN = 1.4, 8 PN = µa AC Electrical Characteristics (STEP-UP. Ta = 25ºC PARAMETER SYMBOL TEST CONDTON MN. TYP. MAX. UNT Output oltage (9 Set O(9 + = 4.5, O = 10mA Load Regulation (9 Set O- O (9 + = 4.5, O = 2 to 17mA m Line Ragulation (9 Set O- N (9 + = 4.5 to 8.1, O = 10mA m Output oltage (5 Set LED (L + = 2.6, O = 10mA Output oltage (24 Set LED (H + = 12, O = 4mA TEST CRCUT D2:SBD (EK er

4 TYPCAL APPLCATON 1. Step-Up Switching Regulator (Low Current 2. Step-Up Switching Regulator (High Current er

5 TYPCAL APPLCATON 3. Step-Down Switching Regulator 4. nverting Switching Regulator er

6 DESGN EQUSTONS Component Step Up Step Down nverting R 1 R 1 =R 3 10 R 1 =R 3 10 R 1 =R 3 10 R 2 5µA TH REF 5µA TH REF 5µA TH REF R 3 REF 1 REF 1 1 R 4 REF 1 R 5 261Ω 261Ω 261Ω REF 1 REF 1 Cx (pf FO (Hz F O F O Lx 0.3 ( FO LOAD 0.3 ( F O LOAD 0.3 FO LOAD ( + C LOAD(2 FO R 2 4F LOAD O R 0.15 F O LOAD 2 ( ( R R 6 35 LOAD 35 LOAD LOAD 35 ( + R 7 5 ( LOAD 2 5 LOAD LOAD 5 ( ( 2 + R LOAD R 9 50( LOAD 2 1 = 100µA TH : low battery detection voltage. Ripple oltage at R : 1 = 50 to 100µA. er

7 DESCRPTON The is a micro-power switching regulator control C suitable for a equipment of battery operation and may be used as step-up, step-down and inverting regulators. The contains a reference, oscillator, amplifier, comparator, detector of input voltage drop and switching transistor. The output voltage is controled by PWM method. The applies a bandgap as a reference voltage. The oscillator is composed of putting one capacitance (Cx to the pin 2. The amplifier is 80dB open-loop voltage gain and 1MHz band width. By adding adequate resistors to the pin 1, the indicating signal comes when the input voltage drops more than designed input voltage. Switching transistor is open collector. TERMNAL DESCRPTON TERMNAL NO. TERMNAL TEMS FUNCTON NSDE EQUALENT CRCUTS 1 nput of oltage Drop Detector nverting input Terminal of comparator-3. When input voltage drops than non-inverting input voltage, comparator drives indicator output transistor. 8 Output of oltage Drop Detecctor Open collector output transistor for driving LED, LCD etc er

8 TERMNAL DESCRPTON TERMNAL NO. TERMNAL TEMS FUNCTON NSDE EQUALENT CRCUTS 2 Timing C Connecting timing for deciding oscillator frequency. 3 Switching Transistor Output Open collector Output of switching transistor. 4 GROUND Ground 5 + Supply voltage terminal. er

9 TERMNAL DESCRPTON TERMNAL NO. TERMNAL TEMS FUNCTON NSDE EQUALENT CRCUTS 6 NF2 Terminal from connecting point of AMP output and COMP-1 inverting input. 7 NF1 nverting input of amplifier er

10 PRNCPLE OF OPERATON The circuit block is shown on Fig. 1 and timing chart on Fig. 2. Function of COMP-2 is setting dead-time. At point A is the square wave and at point B is the triangular wave. By putting two input signals (A, B into COMP-2, output (point C voltage is held high level during rising period of triangular wave and the switching transistor is kept in the off condition regardless the COMP-1 output level. So the maximum duty cycle of the is 50%. The COMP-1 makes on-time of switching transistor longer when the output voltage is high and shorter when it is low. Thus function of the COMP-1 is pulse wide modulation. When the AMP's output waveform is D, COMP-1 output is like E, and NOR GATE output becomes high level only when both inputs, C, E, are low, and so the falling period of triangular wave is the range of pulse width control. D E B A C F A D B E C F er

11 MNMUM OPERATNG OLTAGE Minimum operating voltage is at 25 C and its temperature coefficient is negative. Be careful when you design. Less than this minimum operating voltage, internal switching transistor becomes on, and the surge-like high current flows into it especially in Step-Up or nverting application. OSCLLATOR Oscillator frequency is decided by putting a capacitor into PN 2. The amplitude of both square wave A and triangular wave B is between 1 BE and 3 BE. AMPLFER AMP source current it 20 µa max. and so the feedback resistor R 1 to be connected to PN 6 and PN 7 are recommended more than 100kΩ. SWTCHNG TRANSSTOR When the negative voltage more than 0.5 absolute value based on ground level is applied, the may operate unordinary by reason of parasitic effect in it. And so put SBD in between PN 3 and ground when you drive directory coil with internal switching transistor. DETECTON CRCUT OF NPUT OLTAGE DROP When input voltage becomes lower than specified voltage, transistor Q 56 switches on and indicative device like LED turns on. The specified voltage is decided by internal reference voltage and outer resistors ratio. TH = REF (1+R2/R5 + R2 x 0.5µA When - input voltage becomes lower than + input voltage, PN 1 of COMP-3 sinks about 1µA and thus prevents chattering. Transistor Q56 becomes off condition when PN 1 voltage is lower than about 0.2. t is recommendable to put about 1µF to PN 1 in actual application to avoid switching noise er

12 EFFCENCY Efficiency is shown below. Set Up = N S N x + D S Step Down = N S + N D x + D nverting = N S N x + D S : oltage Drop based on switching transistor On-Resistance. D : Diode Forward oltage Drop. f S and D are low, efficiency increase. Also speed of switching transistor and diode, series resistance of L will affect to it. Example is shown on typical characteristic graph. TEST CRCUT 2 ( : 9 PARAMETER D1 EK-14 S1588 LX = 470µH L1 : ngernal Resistance = 0.2Ω L2 : ngernal Resistance = 2Ω L3 : ngernal Resistance = 7Ω er

13 TYPCAL CHARACTERSTCS Operating Current Reference oltage Operating Frequency Operating Frequency Switching Tr Saturation oltage CE (No. 8 Pin er

14 TYPCAL CHARACTERSTCS Minimum Operating nput oltage oltage Gain No.1 Pin nput Current er

15 TYPCAL CHARACTERSTCS (APPLCATON Output oltage Efficiency Output oltage Output oltage er

16 TYPCAL CHARACTERSTCS (Test Circuits 2 Efficiency Output oltage Efficiency Output oltage nput Current Output oltage er

17 [CAUTON] The specifications on this databook are only given for information, without any guarantee as regards either mistakes or omissions. The application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights er