Advanced Power Electronics Corp. APE8968 3A ULTRA LOW DROPOUT LINEAR REGULATOR FEATURES DESCRIPTION Ultra Low Dropout - 0.23V(typical) at 3A Output Current Low ESR Output Capacitor (Multi-layer Chip Capacitors (MLCC)) Applicable 0.8V Reference Voltage Fast Transient Response Adjustable Output Voltage by External Resistors Power-On-Reset Monitoring on Both VCNTL and VIN Pins Internal Soft-Start Under-Voltage Protection Current-Limit and Thermal Shutdown Protection Power-OK Output with a Delay Time ESOP-8 Pb-Free & Halogen-Free Package. The APE8968 is a 3A ultra low dropout linear regulator. This product is specifically designed to provide well supply voltage for front-side-bus termination on motherboards and NB applications. The IC needs two supply voltages, a control voltage for the circuitry and a main supply voltage for power conversion, to reduce power dissipation and provide extremely low dropout. The APE8968 integrates many functions. A Power-On-Reset (POR) circuit monitors both supply voltages to prevent wrong operations. A thermal shutdown and current limit functions protect the device against thermal and current over-loads. A POK indicates the output status with time delay which is set internally. It can control other converter for power sequence. The APE8968 can be enabled by other power system. Pulling and holding the EN pin below 0.4V shuts off the output. The APE8968 is available in ESOP-8 packages which features small size as an Exposed Pad to reduce the junction-to-case resistance, being applicable in 2~3W applications. TYPICAL APPLICATION 1.Using an Output Capacitor with ESR > 20mΩ R3 1K U1 VCNTL=5V VCNTL VIN=1.5V VIN C2 ON VOUT POK 100 uF 0.1uF VOUT EN C1 C3 OFF GND FB Vout=1.2V/3 A 1uF APE 8968 R1 1K C6 12~48nF C4 C5 220 uF 0.1u R2 2K 2.Using an MLCC as the Output Capacitor (ESOP-8) R3 10K U2 VCNTL=5V VIN=1.5V VCNTL ON POK EN C1 VIN C3 10uF VOUT VOUT Vout=1.2V/3A OFF GND FB 1uF APE8968 R1 39K VOUT=VFB x (1+R1/R2) VFB = 0.8V R2 78K Data and specifications subject to change without notice C6 56pF C5 10uF 1 20130703V3.1 Advanced Power Electronics Corp. APE8968 ABSOLUTE MAXIMUM RATINGS (at TA=25°C) VCNTL Supply Voltage(VCNTL) -------------------------- -0.3V to 7V VIN Supply Voltage(VIN) ---------------------------------- -0.3V to 6V EN and FB Pin Voltage(VI/O) ---------------------------- -0.3V to VCNTL+0.3V Power Good Voltage(VPOK) ------------------------------ -0.3V to 7V Power Dissipation(PD) ------------------------------------ 2.5W Storage Temperature Range(T ST) --------------------- -65°C to +150°C Junction Temperature Range(T J) ---------------------- -40°C To 125°C Operating Temperature Range (T OP) ----------------- -40°C to +85°C Thermal Resistance from Junction to Case(Rth JC) 15°C/W Thermal Resistance from Junction to Ambient(RthJA) 40°C/W Note: Rthja is measured with the PCB copper area (need connect to Expose-Pad) of approximately 1.5 in 2 (Multi-layer) RECOMMENDED OPERATING CONDITIONS VCNTL Supply Voltage(VCNTL) -------------------------- 3V to 5.5V VIN Supply Voltage(VIN) ---------------------------------- 1.2V to 3.65V Output Voltage(VOUT) ------------------------------------- 0.8V to VIN-VDROP (VCNTL - VOUT > 1.9V) Output Current(IOUT) --------------------------------------- 0 to 3A ORDERING/PACKAGE INFORMATION ( Top View ) APE8968X Package Type MP : ESOP-8 GND 1 FB 2 VOUT 3 VOUT 4 8 EN Exposed Pad 7 POK 6 VCNTL 5 VIN ESOP-8 ELECTRICAL SPECIFICATIONS (VCNTL = 5V, VIN = 1.5V, VOUT = 1.2V, TA=25°C unless otherwise specified) MIN TYP MAX UNITS VCNTL 2.5 2.7 2.9 V VCNTL(hys) - 0.4 - V VIN POR Threshold VIN 0.8 0.9 1 V VIN POR Hysteresis VIN(hys) - 0.5 - V EN= VCNTL - 1 1.8 mA - 15 30 uA 0.784 0.8 0.816 V % Parameter SYM VCNTL POR Threshold VCNTL POR Hysteresis VCNTL Nominal Supply Current ICNTL TEST CONDITION VCNTL Shuntdown Current ISD EN= 0V Feedback Voltage VFB VCNTL=3V ~ 5.5V, IOUT =10mA Load Regulation Dropout Voltage IOUT=0A ~ 3A VDROP IOUT = 3A, VCNTL=5V, - 0.2 0.5 1.2V < VOUT < 1.8V - 0.23 0.28 1.8V < VOUT < 2.5V - 0.28 0.33 2.5V < VOUT < 2.8V VOUT Pull Low Resistance Soft Start Time EN=0V TSS V - 0.33 0.38 - 50 - Ω - 2 4 ms 2 Advanced Power Electronics Corp. APE8968 ELECTRICAL SPECIFICATIONS (Cont.) Parameter SYM EN Pin Logic High Threshold Voltage VENH VENL TEST CONDITION TYP MAX Enable 1.2 - - Disable - - 0.4 - 50 - mV - 10 - uA 4.3 - - A - 65 - - 60 - VFB Falling - 0.4 - V EN Hysteresis EN Pin Pull-Up Current IEN EN=GND Current Limit ILIM VCNTL=3~5.5V, TJ= -40 ~ 125°C Ripple Rejection VIN VCNTL F=120Hz, IOUT=100mA PSRR Under-Voltage Threshold UNITS MIN V dB POK Threshold Voltage for Power OK VPOK VFB Rising 89% 92% 95% VFB POK Threshold Voltage for Power Not OK VPNOK VFB Falling 79% 82% 85% VFB - 0.25 0.4 V ms POK Low Voltage POK sinks 5mA POK Delay Time TDELAY 0.8 2 4 TSD - 150 - - 50 - Thermal Shutdown Temp Thermal Shutdown Hysteresis °C PIN DESCRIPTIONS PIN SYMBOL GND PIN DESCRIPTION GND Pin FB Feedback Pin Internal Pull High. EN EN=High or Floating à Enable EN=Low à Shutdown mode VOUT Output Voltage pin POK Power OK Output Pin VCNTL CNTL Pin Input Voltage VIN Input Voltage EP Connect to VIN or GND BLOCK DIAGRAM N-MOSFET VIN VCNTL EN Current Limit Power -ON Reset Enable Error Amp - Soft-Start And Control Logic VOUT + Bandgap UV + FB 0.4V + Thermal Shutdown Delay POK - GND 92% Vref POK 3 Advanced Power Electronics Corp. APE8968 FUNCTION PIN DESCRIPTION FB Connecting this pin to an external resistor divider as the feedback voltage of the regulator. The output voltage set by the resistor divider is determined by: VOUT = 0.8 x (1 + R1/R2) Where R1 is connected from VOUT to FB with Kelvin sensing and R2 is connected from FB to GND. A bypass capacitor may be connected with R1in parallel to improve load transient response. The recommended R2 and R1 are in the range of 1K~100KΩ. VIN Main supply input pins for power conversions. The voltage at this pin is monitored for Power-On Reset purpose. VCNTL Connecting this pin to a +5V (recommended) supply voltage provides the bias for the control circuitry. The voltage at this pin also is monitored for Power-On Reset purpose. POK Power-OK signal output pin. This pin is an open-drain output used to indicate status of output voltage by sensing FB voltage. This pin is pulled low when the rising FB voltage is not above the VPOK threshold or the falling FB voltage is below the VPNOK threshold, indicating the output is not OK. EN Enable control pin. Pulling and holding this pin below 0.4V shuts down the output. When re-enabled, the IC undergoes a new soft-start cycle. Left this pin open, this pin is internally pulled up by VCNTL to enable the regulator. VOUT Output of the regulator. Please connect Pin 3 and Pin 4 using wide tracks. It is necessary to connect an output capacitor with this pin for closed-loop compensation and improving transient responses. FUNCTION DESCRIPTION Power-On-Reset A Power-On-Reset (POR) circuit monitors both input voltages at VCNTL and VIN pins to prevent wrong logic controls. The POR function initiates a soft-start process after the two supply voltages exceed their rising POR threshold voltages during powering on. The POR function also pulls low the POK pin regardless the output voltage when the VCNTL voltage falls below its falling POR threshold. Internal Soft-Start An internal soft-start function controls rise rate of the output voltage to limit the current surge at start-up. The typical soft-start interval is about 2ms. Current Limit The APE8968 monitors the current via the output NMOS and limits the maximum current to prevent load and APE8968 from damages during overload or short circuit conditions. 4 Advanced Power Electronics Corp. APE8968 FUNCTION DESCRIPTION(Cont.) Output Voltage Regulation An error amplifier working with a temperature compensated 0.8V (0.5V/A ) reference and an output NMOS regulates output to the preset voltage. The error amplifier designed with high bandwidth and DC gain provides very fast transient response and less load regulation. It compares the reference with the feedback voltage and amplifies the difference to drive the output NMOS which provides load current from VIN to VOUT. Under Voltage Protection (UVP) The APE8968 monitors the voltage on FB pin after soft-start process is finished. Therefore the UVP is disabling during soft-start. When the voltage on FB pin falls below the under-voltage threshold, the UVP circuit shuts off the output immediately. After a while, the APE8968 starts a new soft-start to regulate output. Thermal Shutdown A thermal shutdown circuit limits the junction temperature of APE8968. When the junction temperature exceeds +150 ° C, a thermal sensor turns off the output NMOS, allowing the device to cool down. The regulator regulates the output again through initiation of a new soft-start cycle after the junction temperature cools by 25°C, resulting in a pulsed output during continuous thermal overload conditions. The thermal shutdown designed. PCB Layout Consideration It is necessary to solder the exposed pad to Vin or Gnd plane as a heat sink and ensure it have enough cooper plane to radiate the thermal. Input capacitor, output capacitor, voltage divider and bypass capacitor need to place near IC as close as possible to decouple the high frequency ripple and noise. The traces shall be short and wide to minimize the parasitic resistance and inductance. Besides, the application circuit shall be close to the load for excellent load transient response. VIN CIN VIN VCNTL VOUT VOUT VOUT COUT VCNTL CCNTL C1 GND R1 FB R2 5 Advanced Power Electronics Corp. APE8968 TYPICAL PERFORMANCE CHARACTERISTICS START UP WAVEFORM -1 VCNTL READY VCNTL=5V VIN=1.5V VOUT=1.2V IOUT=1A VCNTL=5V VIN=1.5V VOUT=1.2V IOUT=100mA START UP WAVEFORM -2 VIN READY VCNTL=5V VIN=1.5V VOUT=1.2V IOUT=100mA VCNTL=5V VIN=1.5V VOUT=1.2V IOUT=2A VCNTL=5V VIN=1.5V VOUT=1.2V IOUT=100mA EN OFF → ON VCNTL=5V VIN=1.5V VOUT=1.2V IOUT=2A 6 Advanced Power Electronics Corp. APE8968 TYPICAL PERFORMANCE CHARACTERISTICS VCNTL=5V VIN=1.5V VOUT=1.2V IOUT=0.1~3A LOAD TRANSCENT VCNTL=5V VIN=1.5V VOUT=1.2V IOUT=0.3~2.5A SHORT CIRCUIT RELEASE VCNTL=5V VIN=1.5V VOUT=1.2V IOUT=100mA VCNTL=5V VIN=1.5V VOUT=1.2V IOUT=2A THERMAL SHUT DOWN RELEASE VCNTL=5V VIN=1.5V VOUT=1.2V IOUT=100mA VCNTL=5V VIN=1.5V VOUT=1.2V IOUT=2A 7 Advanced Power Electronics Corp. APE8968 TYPICAL PERFORMANCE CHARACTERISTICS VCNTL=5V VIN=1.5V VOUT=1.2V IOUT=100mA POK VS. DISABLE VCNTL=5V VIN=1.5V VOUT=1.2V IOUT=0A DROPOUT VOLTAGE VS. OUTPUT CURRENT VCNTL=5V, IOUT=0mA to 3A 8 Advanced Power Electronics Corp. APE8968 MARKING INFORMATION ESOP-8 Part Number Package Code 8968MP YWWSSS Date Code (YWWSSS) Y：Last Digit Of The Year WW：Week SSS：Sequence 9