AP1623 ANACHIP | Alldatasheet
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PWM Control Step-Down Switching Regulator-Converter This datasheet contains new product information. Anachip Corp. re serves the rights to modify the product specification without notice. No liability is assumed as a result of the use of this product. No rights under any patent accompany the sale of the product. Rev. 0.1 Feb 10, 2004 Features - Low current consumption: In operation: 60µA max. Power off: 0.5µA max. - Input voltage: 2.5V to 16V. - Output voltage: 1.8V & Adjustable to 6V. - Duty ratio: 0% to 100% PWM control - Oscillation frequency: 180KHz typ. - Soft-start function: 8ms typ. - With a power-off function. - Built-in internal SW P-channel MOS - SOP-8L Package. Applications - On-board power supplies of battery devices for portable telephones, electronic notebooks, PDA, and other hand-held sets. - Power supplies for audio equipment, including portable CD players and headphone stereo equipment. - Fixed voltage power supply for cameras, video equipment and communications equipment. - Power supplies for microcomputers. - Conversion from four Ni-H or Ni-Cd cells or two lithium-ion cells to 3.3V/3V. - Conversion of AC adapter input to 5V/3V. General Description AP1623 consists of CMOS step-down switching regulator-controllers with PWM control. These devices include a reference voltage source, oscillation circuit, error amplifier, internal PMOS and etc. AP1623 provides low-ripple power, high efficiency, and excellent transient characteristics. The PWM control circuit is able to very the duty ratio linearly from 0 up to 100. This converter also contains an error amplifier circuit as well as a soft-start circuit that prevent s overshoot at startup. With the addition of an internal P-channel Power MOS, a coil, capacitors, and a diode connected externally, these ICs can function as step-down switching regulators. They serve as ideal power supply units for portable devices when coupled with the SOP–8L mini-package, providing such outstanding features as low current consumption. Since this converter can accommodate an input voltage of up to 16V, it is also ideal when operating via an AC adapter. Pin Assignments VOUT SWVCC AP1623 SW ON/OFF Vss Vss PVCC Pin Descriptions Name Pin Description VOUT 1 Output voltage monitoring pin ON/OFF 2 Power-off pin H: Normal operation (Step-down operation) L: Step-down operation stopped (All circuits deactivated) VCC 3 IC signal power supply pin PVCC 4 IC power supply pin SW 5、6 Switch Pin. Connect external inductor/diode here. Minimize trace area at this pin to reduce EMI. VSS 7、8 GND Pin
PWM Control Step-Down Switching Regulator-Converter Anachip Corp. Ordering Information AP 1623 X X X Package Packing S: SOP-8L Blank : Tube A : Taping Lead Free Blank : Normal L : Lead Free Package Block Diagram Oscillation Circuit Reference Voltage Source with Soft Start PWM-Switched Control Circuit COUT VOUT VSSVON/OFF ON/OFF SD L CPVCCVIN VCC SD SWPVCC CVCC R Absolute Maximum Ratings Symbol Parameter Rating Unit VCC *1 VCC pin voltage V SS - 0.3 to VSS + 18 V PVCC PV CC pin voltage V SS - 0.3 to VSS + 18 V VOUT VOUT pin voltage V SS - 0.3 to VSS + 18 V VON/OFF *1 ON/OFF pin voltage V SS - 0.3 to VSS + 18 V VSW Switch pin voltage V SS - 0.3 to VIN + 0.3 V PD Power dissipation 800 mW TOPR Operating temperature range -20 to +85 oC TSTG Storage temperature range -20 to +125 oC Caution: The absolute maximum ratings are rated values exceeding which the product could suffer physical damage. These values must therefore not be exceeded under any conditions.
PWM Control Step-Down Switching Regulator-Controllers Anachip Corp. Electrical Characteristics (VIN = 5V, Ta=25°C, unless otherwise specified) Symbol Parameter Conditions Min. Typ. Max. Unit VOUT(E) Output voltage *1 - VOUT(S) ×0.976 VOUT(S) VOUT(S) ×1.024 V VIN Input voltage AP1623 Series 2.5 -- 16 V ISW Switch Current Duty = 50% 3 -- -- A ISS1 Current consumption 1 V OUT=VOUT(S) ×1.2 -- 35 60 µA ISSS Current consumption during power off V ON/OFF =0V -- -- 0.5 µA ∆VOUT1 Line regulation V IN=VOUT(S) ×1.2 to ×1.4 *2 -- 30 60 mV ∆VOUT2 Load regulation Load current=10µA to IOUT(See below) ×1.25 -- 30 60 mV ∆VOUT /∆Ta Output voltage temperature coefficient Ta= -40°C to 85°C -- ±VOUT(S) ×5E-5 -- V/°C VOUT(S)≥ 2.5V 153 180 207 fOSC Oscillation frequency Measure waveform at SW pin VOUT(S)≤ 2.4V 144 180 216 KHz VSH Evaluate oscillation at SW pin 1.8 -- -- VSL Power-Off pin input voltage Evaluate oscillation stop at SW pin -- -- 0.3 V ISL Power-Off pin input leakage current -- -0.1 -- 0.1 µA TSS Soft-Start time -- 4.0 8.0 16.0 ms EFFI Efficiency V IN = 5V, VOUT = 2.5V IOUT = 1A -- 93 -- % Conditions: The recommended components are connected to the IC, unless otherwise indicated. VIN=VOUT(S) ×1.2[V], IOUT=120[mA] (VIN=2.5V, if VOUT(S) ≤ 2.0V.) Peripheral components: Coil : Sumida Electric Co., Ltd. CD54 (47 µH). Diode : Matsushita Electronics Corporation MA720(Schottky type). Capacitor : Matsushita Electronics Corporation TE (16V, 22 µF tantalum type). The power-off pin is connected to VIN. Notes: The output voltage indicated above represents a typical output voltage set up. These specifications apply in common to AP1623, unless otherwise noted. *1 VOUT(S) Specified output voltage value. V OUT(E) Actual output voltage value. *2 VIN=2.5V to 2.94V, if VOUT(S) ≤ 2.0V.
PWM Control Step-Down Switching Regulator-Controllers Anachip Corp. Typical Application Circuit （1） Normal Application Oscillation Circuit Reference Voltage Source with Soft Start PWM-Switched Control Circuit AP1623 + VSS ON/OFF CC RA RB OUT VOUT PVCC SW VCC RVCC CVCC （2） Application with Short Circuit Protection AP1623 -VSS ON/OFF CC RA RB VOUT : 1.8V VOUT PVCC SW VCC DVCC 1N4148 for above 5V Vin and Schottky for below 5V Vin CVCC 0.1uF CPVCC 100uF CON/OFF 0.33uF RON/OFF RBias 4.7M RSENCE 47K COUTPUT 100uF VIN : 3.3V~16V Test Circuit A VOUTVCC VSSON/OFF open open VOUTVCC VSSON/OFF Oscillation SW SW PVCC PVCC A VOUTVCC VSSON/OFF V SW PVCC
PWM Control Step-Down Switching Regulator-Controllers Anachip Corp. Function Description PWM Control (AP1623 Series) The AP1623 consists of DC/DC converters that employ a pulse-width modulation (PWM) system. In converters of the AP1623, the pulse width varies in a range from 0 to 100, according to the load current, and yet ripple voltage produced by the switching can easily be removed through a filter because the switching frequency remains constant. Therefore, these converte rs provide a low-ripple power over broad ranges of input voltage and load current. External adjustment of output voltage The AP1623 allows the user to select 3 types of the output voltage, when external resistances R A, R B, and capacitor CC are added, as illustrated in Typical Application Circuit. Moreover, a temperature gradient can be obtained by inserting a thermal-resistor or other element in series with R A and RB. Therefore, the output voltage (OUT) is determined by the output voltage value VOUT of the AP1623, and the ratio of the parallel resistance value of external resistance R B and internal resistance R 1 + R2 of the IC, to external resistance R A. The output voltage is expressed by the following equation: OUT = V OUT + VOUT × RA ÷ (RB // (R1+ R2)) (Note:// denotes a combined resistance in parallel.) The voltage accuracy of the output OUT set by resistances R A and R B is not only affected by the IC’s output voltage accuracy (VOUT ± 2.4%), but also by the absolute precision of external resistances R A and RB in use and the absolute value deviations of internal resistances R1 and R2 in the IC. Let us designate the maximum deviations of the absolute value of external resistances R A and RB by RAmax and R Bmax, respectively, the minimum deviations by R Amin and R Bmin, respectively, and the maximum and minimum deviations of the absolute value of internal resistances R 1 and R 2 in the IC by (R 1+ R 2)max and (R 1+ R 2)min, respectively. Then, the minimum deviation value OUTmin and the maximum deviation value OUTmax of the output voltage OUT are expressed by the following equations: OUTmin = V OUT × 0.976 + V OUT × 0.976 × R Amin ÷ (RBmax// (R1+ R2)max) OUTmax = VOUT × 1.024 + VOUT × 1.024 × RAmax ÷ (RBmin// (R1+ R2)min) The voltage accuracy of t he output OUT cannot be made higher than the output voltage accuracy (VOUT ± 2.4%) of the IC itsel f, without adjusting the external resistances RA and RB involved. The closer the voltage value of the output OUT and the output voltage value (V OUT) of the IC are brought to one other, the more the output voltage remains immune to deviations in the absolute accuracy of externally connected resistances R A and R B and the absolute value of internal resistances R1 and R2 in the IC. In particular, to suppress the influence of deviations in internal resistances R 1 and R 2 in the IC, a major contributor to deviations in the output OUT, the external resistances R A and RB must be limited to a much smaller value than that of internal resistances R1 and R2 in the IC. On the other hand, a reactive current flows through external resistances R A and R B. This reactive current must be reduced to a negligible value with respect to the load current in the actual use of the IC so that the efficiency characteristics will not be degraded. This requires that the value of external resistance R A and RB be made sufficiently large. However, too large a value (more than 1 M Ω) for the external resistances RA and RB would make the IC vulnerable to external noise. Check the influence of this value on actual equipment. There is a tradeoff between the voltage accuracy of the output OUT and the reactive current. This should be taken into consideration based on the requirements of the intended application. Deviations in the absolute value of internal resistances R1 and R2 in the IC vary with the output voltage of the AP1623, and are broadly classified as follows: . Output voltage 2.5V → 4.44M Ω to 27.0MΩ . Output voltage 3.3V → 3.60M Ω to 23.3MΩ . Output voltage 5.0V → 2.45M Ω to 2.45MΩ When a value of R 1+R2 given by the equation indicated below is taken in calculating the voltage value of the output OUT, a median voltage deviation will be obtained for the output OUT. R 1 + R 2 = 2 ÷ ( 1 ÷ maximum deviation in absolute value of internal resistances R 1 and R 2 in IC + 1 ÷ minimum deviation in absolute value of internal resistances R1 and R2 of IC) Moreover, add a capacitor C C in parallel to the external resistance R A in order to avoid output oscillations and other types of instability. Make sure that C C is larger than the value given by the following equation: CC(F) ××2(÷1 π≥ RA )5.7×)Ω( kHz If a large C C-value is selected, a longer soft-start time than the one set up in the IC will be set.
PWM Control Step-Down Switching Regulator-Controllers Anachip Corp. Marking Information SOP-8L ( Top View ) Logo Part no. ID code: internal Year: "01" =2001 "02" =2002 Xth week: 01~52 ~1 4 8 5 AC AP1623 YY WW X X Blank: normal L: Lead Free Package Package Information Package Type: SOP-8L VIEW "A" L C VIEW "A" H E A A2A1Be D 7 (4X) 0.015x45 7 (4X) y A1 0.10 − 0.25 0.040 − 0.100 θ 0O − 8O 0 O − 8O