Advanced Power Electronics Corp. APE8951 1.5A ULTRA LOW DROPOUT LINEAR REGULATOR FEATURES DESCRIPTION Ultra Low Dropout Voltage 250mV at 1.5A Output Current Low ESR Output Capacitor (MLCC) Applicable 0.8V Reference Voltage Fast Transient Response Current Limit and Thermal Shutdown Protection Adjustable Output Voltage by External Resistors Power-on-Reset Monitoring on Both VCNTL and VIN Pins Under Voltage Protection Power OK Output with a Delay Time Internal Soft-Start SOP-8 with Exposed Pad Package RoHS Compliant & Halogen Free The APE8951 is a 1.5A ultra low dropout linear regulator. The product is specifically designed to provide well supply voltage for front side bus termination on motherboard and NB applications. The IC needs two supply voltages, a voltage for the circuitry and a main supply voltage for power conversion, to reduce power dissipation and provide extremely low dropout. The APE8951 integrates many functions. A Power-on-Reset(POR) circuit monitors both supply voltage to prevent wrong operations. A thermal shutdown and current limit functions protect the device against thermal and current over-load. A POK indicates the output status with time delay which is set internally. It can control other converter for power sequence. The APE8951 can be enabled by other power system. Pulling and holding the EN pin below 0.4V shuts off the output. The APE8951 is available in ESOP-8 package which features small size as SO-8 and exposed pad to reduce the junction-to-case resistance, being applicable in 2~3W applications. TYPICAL APPLICATION R3 1K R3 1K VCNTL=5V 6 7 C1 1uF VCNTL VIN POK VOUT VIN=1.5V 5 C4 220uF 4 1 EN GND VOUT FB 2 7 VOUT=1.2V/1.5A 3 R1 1K C6 12~48nF 6 C3 0.1uF APE8951 8 VCNTL=5V C1 1uF VCNTL VIN POK VOUT VIN=1.5V 5 C2 22uF 4 APE8951 8 EN VOUT VOUT=1.2V/1.5A 3 R1 39K C4 220uF R2 2K Figure 1. Output Capacitor with ESR > 20mΩ C5 0.1uF 1 GND VOUT=VFB x (1+R1/R2) VFB=0.8V FB 2 C4 56pF C3 22uF R2 78K Figure 2. Output Capacitor is MLCC ORDERING INFORMATION APE8951X - HF Package Type MP : ESOP-8 Halogen Free Data and specifications subject to change without notice 1 20100107D Advanced Power Electronics Corp. APE8951 ABSOLUTE MAXIMUM RATINGS VCNTL Supply Voltage(VCNTL) --------------------------- -0.3 to 7 V VIN Supply Voltage(VIN) ----------------------------------- -0.3 to 3.3 V EN and FB Pin Voltage ------------------------------------ -0.3 to VCNTL + 0.3V Power Good Voltage(VPOK) ------------------------------- -0.3 to 7 V Power Dissipation(PD) -------------------------------------- 3 W Storage Temperature Range(T ST) ---------------------- -65°C To 150°C Junction Temperature Range(T J) ----------------------- -25°C To 150°C Operating Temperature Range(T OP) ------------------- -20°C To + 85°C Thermal Resistance from Junction to Case(Rth JC) - 15°C/W Thermal Resistance from Junction to Ambient(Rth JA) 40°C/W Note. Rth JA is measured with the PCB copper area(need connect to Exposed pad) of approx. 1.5 in 2 (multi-layers) RECOMMENDED OPERATING CONDITIONS VCNTL Supply Voltage(VCNTL) --------------------------- +3.1 to 6 V VIN Supply Voltage(VIN) ----------------------------------- +1.1 to 3.3 V Output Voltage(VOUT) VCNTL=3.3V +0.8 to 1.2 V VCNTL=5V +0.8 to VIN-0.2 V Output Current(I OUT) ---------------------------------------- +0 to 1.5 A Junction Temperature Range(T J) ----------------------- -25°C To 125°C PACKAGE INFORMATION ELECTRICAL SPECIFICATIONS ( VCNTL=5V, VIN=1.5V, VOUT=1.2V, TA=25oC, unless otherwise specified) Parameter VCNTL POR Threshold SYM TEST CONDITION VCNTL(PORTH) MIN TYP MAX UNITS 2.7 2.9 3.1 V VCNTL POR Hysteresis VCNTL(hys) - 0.4 - V VIN POR Threshold VIN(PORTH) VIN(hys) 0.8 0.9 1.0 V VIN POR Hysteresis VCNTL Nominal Supply Current ICNTL VCNTL Shutdown Current ISD Feedback Voltage VFB Load Regulation Dropout Voltage VDROP EN=VCNTL EN=0V - 0.5 - V 0.4 1 2 mA - 18 30 uA VCNTL=3.3 ~ 5V 0.784 0.8 0.816 V IOUT = 0A ~ 1.5A - 0.06 0.25 % IOUT = 1.5A, VCNTL=5V, TJ=25oC - 0.23 0.3 V IOUT = 1.5A, VCNTL=5V, TJ=25~125oC - - 0.3 V 2 Advanced Power Electronics Corp. APE8951 ELECTRICAL SPECIFICATIONS(Cont.) Soft Start Time TSS EN Pin Logic High Threshold VENH Voltage EN Hysteresis EN Pin Pull-Up Current Enable IEN Current Limit EN=GND o ILIM VCNTL=3.3 ~ 5V, TJ=25 C ms 0.4 0.8 1.2 V - 30 - mV - 10 - uA 3 4 A 2 - - A VFB Falling - 0.4 - V VPOK VFB Rising 89% 92% 95% VFB VPNOK VFB Falling 78% 81% 84% VFB POK Sinks 5mA TDELAY Thermal Thutdown Temp - 2 POK Low Voltage POK Delay Time 2 VCNTL=3.3 ~ 5V, TJ=-25~125 C o Under Voltage Threshold POK Threshold Voltage for Power OK POK Threshold Voltage for Power Not OK - TSD Thermal Thutdown Hysteresis - 0.25 0.4 V 0.8 2 10 ms - 150 - ºC - 50 - ºC PIN DESCRIPTIONS PIN SYMBOL GND PIN DESCRIPTION GND Pin FB Feedback Pin VOUT IC Power Supply Pin EN H : Normal Operation ; L : Shutdown POK Power OK Output Pin VCNTL CNTL Pin Input Voltage VIN Input Voltage 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 90% Vref POK 3 Advanced Power Electronics Corp. APE8951 FUNCTION PIN DESCRIPTION FB Connecting this pin to an external resistor divider receives 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 R1 in parallel to improve load transient response. The recommended R2 and R1 are in the range of 1k~100kohm. VIN and Exposed Pad Main supply input pins for power conversions. The exposed pad provides a very low impedance input path for the main supply voltage. Please tie the exposed pad and VIN Pin (Pin 5) together to reduce the dropout voltage. The voltage at this pin is monitored for Power-On Reset purpose. VCNTL Power input pin of the control circuitry. Connecting this pin to a +5V(recommended) supply voltage provides the bias for the control circuitry. The voltage at this pin 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, an internal current source 10uA pulls this pin up to VCNTL voltage, enabling the regulator. VOUT Output of the regulator. Please connect Pin 3 and 4 together using wide tracks. It's necessary to connect an output capacitor with this pin for closed-loop compensation and improving transient responses. FUNCTION DESCRIPTION Power-On-Reset 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 it’s 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 APE8951 monitors the current via the output NMOS and limits the maximum current to prevent load and APE8951 from damage during overload or short circuit 4 Advanced Power Electronics Corp. APE8951 FUNCTION DESCRIPTION(Cont.) Output Voltage Regulation An error amplifier working with a temperature compensated 0.8V 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 APE8951 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 APE8951 starts a new soft-start to regulate output. Thermal Shutdown A thermal shutdown circuit limits the junction temperature of APE8951. 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 50°C, resulting in a pulsed output during continuous thermal overload conditions. 5 Advanced Power Electronics Corp. APE8951 TYPICAL PERFORMANCE CHARACTERISTICS Dropout Voltage vs. Output Current VCNTL Supply Current vs. Temperature 1.6 125℃ 100℃ 75℃ 50℃ 25℃ 0℃ -25℃ -40℃ 140 120 100 80 60 1.4 ICNTL(mA) Dropout Voltage (mV) 160 1.2 1 0.8 0.6 40 0.4 20 0.2 0 0 0 300 600 900 1200 1500 -40 -25 0 25 50 75 100 125 100 125 Temperature(℃) IOUT(mA) Reference Voltage vs. Temperature Current Limit vs. Temperature 2.39 0.814 2.38 2.37 Current Limit (A) VFB(V) 0.809 0.804 0.799 0.794 0.789 0.784 -40 2.36 2.35 2.34 2.33 2.32 2.31 2.3 -25 0 25 50 75 100 125 -40 -25 0 25 50 75 Temperature (℃) Tem perature(℃ ) EN Pin Floating Test Current Limit VOUT VIN VCNTL VPOK VOUT IOUT Ch1 : VOUT, 500mV/Div Ch2 : IOUT, 1A/Div Time : 2ms/Div Ch1 : VIN, 1V/Div Time : 1ms/Div Ch2 : VCNTL, 5V/Div Ch3 : VPOK, 1V/Div Ch4 : VOUT, 1V/Div 6 Advanced Power Electronics Corp. APE8951 TYPICAL PERFORMANCE CHARACTERISTICS Power ON Sequence Power OFF Sequence VIN VIN VOUT VOUT VPOK VCNTL VCNTL VPOK Ch1 : VIN, 1V/Div Ch2 : VOUT, 1V/Div Ch3 : VPOK, 1V/Div Ch4 : VCNTL, 2V/Div Time : 10ms/Div Enable Sequence Ch1 : VIN, 1V/Div Ch2 : VOUT, 1V/Div Ch3 : VPOK, 1V/Div Ch4 : VCNTL, 2V/Div Time : 10ms/Div Shutdown Sequence VEN VEN VOUT VOUT IOUT VPOK IOUT VPOK Ch1 : VEN, 5V/Div Ch2 : VOUT, 1V/Div Ch3 : IOUT, 1A/Div Ch4 : VPOK, 1V/Div Time : 1ms/Div POK Delay Ch1 : VEN, 5V/Div Ch2 : VOUT, 1V/Div Ch3 : IOUT, 1A/Div Ch4 : VPOK, 1V/Div Time : 1ms/Div Load Transient Response VIN VOUT VCNTL VPOK POK Delay IOUT VOUT Ch1 : VIN, 1V/Div Ch2 : VCNTL, 5V/Div Ch3 : VPOK, 1V/Div Ch4 : VOUT, 1V/Div Time : 500us/Div Ch1 : VOUT, 10mV/Div Ch2 : IOUT, 1A/Div Time : 100us/Div 7 ADVANCED POWER ELECTRONICS CORP. Package Outline : ESOP-8 Millimeters Q P SYMBOLS MIN NOM MAX A 5.80 6.00 6.20 B 4.80 4.90 5.00 C 3.80 3.90 4.00 D 0° 4° 8° E 0.40 0.65 0.90 F 0.19 0.22 0.25 M 0.00 0.08 0.15 H 0.35 0.42 0.49 L 1.35 1.55 1.75 0.375 REF. J B A2 K 45° G 1.27 TYP. P 3.15 3.25 3.35 Q 2.25 2.35 2.45 L I J 1.All Dimension Are In Millimeters. 2.Dimension Does Not Include Mold Protrusions. Part Marking Information & Packing : ESOP-8 Part Number Package Code 8951MP YWWSSS Date Code (YWWSSS) Y：Last Digit Of The Year WW：Week SSS：Sequence 8