0kHz, A PWM Buck DC/DC Converter Features Output voltage: Fixed.V, V, V and adjustable output (.V to.v) versions. Fixed switching frequency, 0KHz ±%. Voltage mode non-synchronous PWM control. Thermal-shutdown and current-limit protection. ON/OFF shutdown control input. Short Circuit Protection (SCP). Operating voltage up to 0V. Output load current up to A. Low-power standby mode. Built-in switching transistor on chip. SO- package RoHS-compliant, halogen-free. Description The series consists of step-down DC-DC converters with the ability to drive a A load without an external switching transistor, saving board space. The external shutdown function can be controlled by logic level signals to put the device in standby mode. The internal compensation allows feedback control for good line and load regulation without external components. Thermal shutdown protection prevents damage from excessive operating temperatures and output current limiting protects the device from damage. Excess current when VFB is below O.V results in reduced switching frequency. The series operate at a switching frequency of 0kHz, allowing smaller sized filter components than with lower frequencies. The APE0-HF- series are available with an adjustable output voltage, or fixed output voltages of.v, V or V, and are supplied in an SO- package. Typical Application VIN=V C C U Vcc FB EN L uh D B0A C C Vout=.0V/A R.K R.K APE0 Ordering information APE0X-XX-HF-TR Packing Type: TR: Tape and reel Package Type: Output Voltage: M: SO- :.V 0:.0V : V Blank: ADJ Examples: APE0M--HF-TR.V fixed output in RoHS-compliant, halogen-free SO-, shipped on tape and reel (000 pcs/reel). APE0M-HF-TB adjustable output in RoHS-compliant, halogen-free SO-, shipped on tape and reel (000 pcs/reel). 000- /0
Absolute Maximum Ratings (at T A = C) Characteristics Symbol Rating Unit Maximum Supply Voltage V CC + V ON/OFF Pin Input Voltage V EN -0. to 0 V Feedback Pin Voltage V FB -0. to V Output Voltage to Ground V OUT 0. to V V Power Dissipation Internally limited PD ( T J -T A ) / θja W Storage Temperature Range T ST - to +0 C Operating Junction Temperature Range T J -0 to + C Operating Supply Voltage V OP +. to +0 V Thermal Resistance from Junction to case θ JC 0 C/W Thermal Resistance from Junction to ambient θ JA 0 C/W Note: RthJA is measured with a PCB copper area (must be connected to VSS pins) of approximately. in (multi-layer). Electrical Characteristics (Unless otherwise specified, T A = C, V CC =V for.v, V, adjustable version and V CC =V for the V version. I LOAD = 0.A) Characteristics Symbol Conditions Min Typ Max Units Quiescent Current I Q V FB =V force driver off ma Feedback bias current I FB V FB =.V (Adjustable version only) -0-0 na Shutdown supply Current I SD EN pin=v V CC =0V 00 00 ua Oscillator frequency F OSC 0 khz Oscillator frequency of short (Adjustable) When V FB <0.V 0 khz F circuit protect SCP (Fixed)When < V OUT *0% 0 khz Max. Duty Cycle (ON) V FB =0V force driver on 00 DC Min. Duty Cycle (OFF) V FB =V force driver off 0 % Current limit I CL Pear current, No outside circuit V FB =0V force driver on. A Load Regulation( V OUT /V OUT ) V OUT I OUT = 0. to A - 0.. % I Saturation voltage V OUT =A, No outside circuit SA T V FB =0V force driver on.. V pin=0v pin No outside circuit leakage I V FB L =V force driver off -00 ua pin=-0.v current V CC =0V force driver off - ma EN pin logic input threshold V IL Low (regulator ON) - 0.. voltage V IH High (regulator OFF).0 - V EN pin logic input current I H V EN =.V (OFF) -0. -0 EN pin input current I L V EN =0.V (ON) -0.0 - ua Thermal shutdown Temp TSD C /0
Electrical Characteristics (cont.) Version Characteristics Symbol Conditions Min Typ Max Units APE0-ADJ Output Feedback voltage V FB ILOAD =0.A VOUT programmed for.v.9.. V Efficiency η V CC = V, ILOAD=A 9 % APE0-.V APE0-.0V APE0-V Output voltage V OUT ILOAD =0.A.0.0.0 V Efficiency η V CC = V, ILOAD=A 0 % Output voltage V OUT ILOAD =0.A..00. V Efficiency η V CC = V, ILOAD=A % Output voltage V OUT ILOAD =0.A..0. V Efficiency η V CC = V, ILOAD = A 90 % THIS PRODUCT IS SENSITIVE TO ELECTROSTATIC DISCHARGE, PLEASE HANDLE WITH CAUTION. USE OF THIS PRODUCT AS A CRITICAL COMPONENT IN LIFE SUPPORT OR OTHER SIMILAR SYSTEMS IS NOT AUTHORIZED. APEC DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. APEC RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. /0
Block Diagram EN 00mV V CC CURRENT SOURCE BIAS.V REFERENCE.V REGULATOR START UP 0mV FB 0kHz OSC. Current limit + COMP. COMP. + R + _ AMP COMP. + COMP. _ CONTROL + DRIVER A ITCH R ADJ : R=0Ω, R=OPEN Thermal Shutdown Pin Assignment Vcc FB EN (Top View) SO- Name V CC FB EN V SS Description Operating voltage input Switching output Output voltage feedback control ON/OFF Shutdown GND pin /0
Typical Application Circuits () Adjustable Output Voltage Version VIN=V C C U Vcc FB EN L uh D B0A C C R.K R.K Vout=.0V/A APE0 () Adjustable Output Voltage Version With Delayed Startup VIN=V C C C U Vcc FB EN L uh D B0A C C R.K R.K Vout=.V/A R 00k ON/OFF APE0 R Vout = VFB ( + ), VFB =.V, R = 0.kΩ ~ kω R Table : Resistor selection for output voltage setting V OUT R R V.V.k.k.k.k.k.k.k.0k.V.k.k.V.k 0.k L recommended value (I OUT =A) V OUT.V.V V V V IN =V uh uh uh NA V IN =V uh uh uh uh /0
Typical Application Circuits (cont.) () Fixed Output Voltage Version VIN=~V C C U Vcc FB EN L uh D B0A C Vout=.V/A C APE0- () Inverting -V Regulator with Delayed Startup VIN=~0V A/0V 0uF uh 0uF Vcc FB A/0V EN 00k APE0-0 00uF IN00 VOUT -V00mA /0
Functional Description Pin Functions Vcc This is the positive input supply for the IC switching regulator. A suitable input bypass capacitor must be present at this pin to minimize voltage transients and to supply the switching currents needed by the regulator. Circuit ground. Internal switch. The voltage at this pin switches between (+V CC V SAT ) and approximately 0.V, with a duty cycle of approximately V OUT / V CC. To minimize coupling to sensitive circuitry, the PC board copper area connected to this pin should be minimized. Feedback Senses the regulated output voltage to complete the feedback loop. EN Allows the switching regulator circuit to be shutdown using logic level signals thus dropping the total input supply current to approximately 00uA. Pulling this pin below a threshold voltage of approximately.v turns the regulator on, and pulling this pin above.v (up to a maximum of Vcc) shuts the regulator down. If this shutdown feature is not needed, the EN pin can be wired to the ground pin. Thermal Considerations The SO- package needs a heat sink under most conditions. The size of the heat sink depends on the input voltage, the output voltage, the load current and the ambient temperature. The APE0 junction temperature rises above ambient temperature for a A load and different input and output voltages. The data for these curves was taken with the APE0 (in SO- package) operating as a buck-switching regulator in an ambient temperature of C (still air). These temperature increments are all approximate and are affected by many factors. Higher ambient temperatures require more heatsinking. /0
Functional Description (cont.) For the best thermal performance, wide copper traces and generous amounts of printed circuit board copper (needs to be connected to the VSS pins) should be used in the board layout, (One exception is the (switch) pin, which should not have large areas of copper.) Large areas of copper provide the best transfer of heat (lower thermal resistance) to the surrounding air, and moving air lowers the thermal resistance even further. Package thermal resistance and junction temperature increments are all approximate. The increments are affected by a lot of factors. Some of these factors include board size, shape, thickness, position, location, and even board temperature. Other factors are: trace width, total printed circuit copper area, copper thickness, single or double-sided, multi-layer board and the amount of solder on the board. The effectiveness of the PC board to dissipate heat also depends on the size, quantity and spacing of other components on the board, as well as whether the surrounding air is still or moving. Furthermore, some of these components such as the catch diode will add heat to the PC board and the heat can vary as the input voltage changes. For the inductor, depending on the physical size, type of core material and the DC resistance, it could either act as a heat sink taking heat away from the board, or it could add heat to the board. /0
Typical Characteristics Output Ripple (V IN =V, V OUT =.V, I OUT =A) Power on test wave (V IN =V, V OUT =V, I OUT =A ) V OUT V OUT (AC) V IN I I Load Transient Response (V IN =V, V OUT =.V, I OUT =0.~A) EN on test wave (V IN =V, V OUT =V, I OUT =A ) V OUT (AC) V OUT V OUT V IN I I Efficiency Efficiency (V IN =V, V OUT =.V) (V IN =V, V OUT =.0V) 90% 0% 0% Vin=V 90% 0% 0% Vin=V Efficiency(%) 0% 0% 0% 0% Efficiency(%) 0% 0% 0% 0% 0% 0% 0% 0% 0% 0.0 0..0..0 Iout(A) 0% 0.0 0..0..0 Iout(A) 9/0
Package Dimensions: SO- D Millimeters SYMBOLS MIN NOM MAX e B E E A... A 0.0 0. 0. B 0. 0. 0. C 0.9 0. 0. D.0.90.00 E.0.90.00 E.0..0 L 0. 0.. θ 0.00.00 e. TYP A A DETAIL A L θ c. All dimensions are in millimeters.. Dimensions do not include mold protrusions. DETAIL A Marking Information: 0M-XX YWWSSS Product: APE0 Package: M = RoHS-compliant halogen-free SO- Output: Blank = adjustable, /0/ = fixed output voltage Date/lot code (YWWSSS) Y: Last digit of the year WW: Work week SSS: Lot code sequence 0/0