AP1623 PWM Control Step-Down Switching Regulator-Converter Features General Description - 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. 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. Applications 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. 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. - 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. Pin Descriptions Pin Assignments 8 Vss 7 Vss VCC 3 6 SW PVCC 4 5 SW VOUT ON/OFF 1 2 Name Pin VOUT 1 ON/OFF 2 AP1623 Description Output voltage monitoring pin 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 Switch Pin. Connect external inductor/diode here. Minimize 5、6 trace area at this pin to reduce EMI. VSS 7、8 GND Pin This datasheet contains new product information. Anachip Corp. reserves 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 1/6 AP1623 PWM Control Step-Down Switching Regulator-Converter Ordering Information X AP 1623 X X Package Lead Free Packing S: SOP-8L Blank : Normal L : Lead Free Package Blank : Tube A : Taping Block Diagram PVCC R L SW Oscillation Circuit VCC Reference Voltage Source with Soft Start + PWM-Switched Control Circuit SD CPVCC + - SD VIN VOUT COUT CVCC VON/OFF VSS ON/OFF Absolute Maximum Ratings Symbol Rating Unit VCC pin voltage VSS - 0.3 to VSS + 18 V PVCC pin voltage VSS - 0.3 to VSS + 18 V VOUT pin voltage VSS - 0.3 to VSS + 18 V ON/OFF pin voltage VSS - 0.3 to VSS + 18 V VSW Switch pin voltage VSS - 0.3 to VIN + 0.3 V PD Power dissipation 800 mW VCC *1 PVCC VOUT VON/OFF TOPR *1 Parameter Operating temperature range -20 to +85 o C o Storage temperature range -20 to +125 TSTG C 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. Anachip Corp. www.anachip.com.tw Rev. 0.1 Feb 10, 2004 2/6 AP1623 PWM Control Step-Down Switching Regulator-Controllers Electrical Characteristics (VIN = 5V, Ta=25°C, unless otherwise specified) Symbol Parameter VOUT(E) Output voltage *1 Conditions - Min. Typ. Max. VOUT(S) VOUT(S) VOUT(S) ×0.976 ×1.024 2.5 -16 Unit V VIN Input voltage AP1623 Series ISW Switch Current Duty = 50% 3 -- -- A ISS1 Current consumption 1 VOUT=VOUT(S) ×1.2 -- 35 60 µA ISSS Current consumption during power off VON/OFF =0V -- -- 0.5 µA VIN=VOUT(S) ×1.2 to ×1.4 *2 Load current=10µA to IOUT(See below) ×1.25 -- 30 60 mV -- 30 60 mV -- V/°C ∆VOUT1 Line regulation ∆VOUT2 Load regulation ∆VOUT /∆Ta fOSC VSH VSL ISH ISL TSS EFFI Output voltage temperature coefficient Oscillation frequency Power-Off pin input voltage Power-Off pin input leakage current Soft-Start time Efficiency Ta= -40°C to 85°C Measure VOUT(S) ≥ 2.5V waveform at VOUT(S) ≤ 2.4V SW pin Evaluate oscillation at SW pin Evaluate oscillation stop at SW pin ---VIN = 5V, VOUT = 2.5V IOUT = 1A 153 ±VOUT(S) ×5E-5 180 207 144 180 216 1.8 -- -- -- -- 0.3 -0.1 -0.1 4.0 -- --8.0 93 0.1 0.1 16.0 -- -- V KHz V µA µA ms % 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 (47µH). Diode : Matsushita Electronics Corporation MA720(Schottky type). Capacitor : Matsushita Electronics Corporation TE (16V, 22µF 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. VOUT(E) Actual output voltage value. *2 VIN=2.5V to 2.94V, if VOUT(S) ≤ 2.0V. Anachip Corp. www.anachip.com.tw Rev. 0.1 Feb 10, 2004 3/6 AP1623 PWM Control Step-Down Switching Regulator-Controllers Typical Application Circuit （1） Normal Application OUT SW PVCC CC RVCC AP1623 VCC + R1 RB + PWM-Switched Control Circuit CVCC RA VOUT - D1 R2 Reference Voltage Source with Soft Start Oscillation Circuit ON/OFF VSS （2） Application with Short Circuit Protection VIN : 3.3V~16V VOUT : 1.8V PVCC SW DVCC 1N4148 for above 5V Vin and Schottky for below 5V Vin RON/OFF 1M CON/OFF 0.33uF RBias 4.7M CC AP1623 VCC VOUT + ON/OFF VSS RB - D1 RSENCE 47K CPVCC CVCC 100uF 0.1uF RA COUTPUT 100uF O scillation Test Circuit open VCC PVCC SW VOUT open A VCC PVCC SW VOUT + A ON/OFF VCC + - SW PVCC ON/OFF - VSS ON/OFF VSS VOUT + V VSS - Anachip Corp. www.anachip.com.tw Rev. 0.1 Feb 10, 2004 4/6 AP1623 PWM Control Step-Down Switching Regulator-Controllers 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 converters 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 RA, RB, 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 RA 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 RB and internal resistance R1 + R2 of the IC, to external resistance RA. The output voltage is expressed by the following equation: OUT = VOUT + VOUT × RA ÷ (RB // (R1+ R2)) (Note:// denotes a combined resistance in parallel.) The voltage accuracy of the output OUT set by resistances RA and RB is not only affected by the IC’s output voltage accuracy (VOUT ± 2.4%), but also by the absolute precision of external resistances RA 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 RA and RB by RAmax and RBmax, respectively, the minimum deviations by RAmin and RBmin, respectively, and the maximum and minimum deviations of the absolute value of internal resistances R1 and R2 in the IC by (R1+ R2)max and (R1+ R2)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 = VOUT × 0.976 + VOUT × 0.976 × RAmin ÷ (RBmax// (R1+ R2)max) OUTmax = VOUT × 1.024 + VOUT × 1.024 × RAmax ÷ (RBmin// (R1+ R2)min) The voltage accuracy of the output OUT cannot be made higher than the output voltage accuracy (VOUT ± 2.4%) of the IC itself, without adjusting the external resistances RA and RB involved. The closer the voltage value of the output OUT and the output voltage value (VOUT) 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 RA and RB and the absolute value of internal resistances R1 and R2 in the IC. In particular, to suppress the influence of deviations in internal resistances R1 and R2 in the IC, a major contributor to deviations in the output OUT, the external resistances RA 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 RA and RB. 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 RA and RB be made sufficiently large. However, too large a value (more than 1 MΩ) 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 → 4.44MΩ to 27.0MΩ . Output voltage 3.3V → 3.60MΩ to 23.3MΩ . Output voltage 5.0V → 2.45MΩ to 2.45MΩ When a value of R1+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. R1 + R2 = 2 ÷ ( 1 ÷ maximum deviation in absolute value of internal resistances R1 and R2 in IC + 1 ÷ minimum deviation in absolute value of internal resistances R1 and R2 of IC) Moreover, add a capacitor CC in parallel to the external resistance RA in order to avoid output oscillations and other types of instability. Make sure that CC is larger than the value given by the following equation: CC(F)≥1 ÷ ( 2 × π × RA (Ω) × 7.5kHz ) If a large CC-value is selected, a longer soft-start time than the one set up in the IC will be set. Anachip Corp. www.anachip.com.tw Rev. 0.1 Feb 10, 2004 5/6 AP1623 PWM Control Step-Down Switching Regulator-Controllers Marking Information ( Top View ) 8 5 AC Logo AP1623 Part no. Blank: normal L: Lead Free Package ID code: internal Xth week: 01~52 Year: "01" =2001 "02" =2002 YY WW X X 1 4 ~ SOP-8L Package Information H E Package Type: SOP-8L L VIEW "A" D 0.015x45 7 (4X) e B A1 C A A2 7 (4X) VIEW "A" y Symbol A A1 A2 B C D E e H L y θ Dimensions In Millimeters Min. Nom. Max. 1.40 1.60 1.75 0.10 0.25 − 1.30 1.45 1.50 0.33 0.41 0.51 0.19 0.20 0.25 4.80 5.05 5.30 3.70 3.90 4.10 1.27 − − 5.79 5.99 6.20 0.38 0.71 1.27 0.10 − − 8O 0O − Anachip Corp. www.anachip.com.tw Dimensions In Inches Min. Nom. Max. 0.055 0.063 0.069 0.040 0.100 − 0.051 0.057 0.059 0.013 0.016 0.020 0.0075 0.008 0.010 0.189 0.199 0.209 0.146 0.154 0.162 0.050 − − 0.228 0.236 0.244 0.015 0.028 0.050 0.004 − − 0O 8O − Rev. 0.1 Feb 10, 2004 6/6