AIC1531 500mA Dual Linear Regulator with Internal Power Switch n FEATURES n DESCRIPTION l Continuous 3.3V Output from Three Inputs. l Complete Power Management Solution. l VCC, VSBY Regulator Supplies 500mA Output. l Built-in Hysteresis When Selecting Input Supplies. l Integrated Switch has Very Low RDS(ON) 120mΩ (typ.). l Integrated Switch Supplies 500mA From VAUX . l Output can be Forced Higher than Input (Off-State). AIC1531 is a dual input regulator with VAUX switch capable of delivering 3.3V/500mA continuously. The output power is provided from three independent input voltage sources on a prioritized basis. Power is always taken in priority using the following order VCC, VSBY, and VAUX . The AIC1531 meets Intel’s “ Instantly Available ” power requirements which follows the “Advanced Configuration n APPLICATIONS and Power Interface“ (ACPI) standards. When either V CC or V SBY is present, the l Desktop Computers. l PCI Adapter Cards with Wake-On-LAN. l Network Interface Cards (NICs). l Multi Power System. l System with Standby Capabilities. device automatically enables the regulator and produces a stable 3.3V output VOUT . When only VAUX (3.3V) is present, the device provides a low impedance direct connection (120mΩ typ.) from VAUX to VOUT . The AIC1531 also prevents excessive current from flowing VOUT to either input voltage or ground when the output voltage is higher than the input voltage. All the necessary control circuitry needed to provide a smooth and automatic transition between all the three supplies has been incorporated. This allows both V CC and V SBY to be dynamically switched without loss of output voltage. Analog Integrations Corporation 4F, 9 Industry E. 9th Rd, Science-Based Industrial Park, Hsinchu, Taiwan TEL: 886-3-5772500 FAX: 886-3-5772510 www.analog.com.tw DS-1531-00 022502 1 AIC1531 n TYPICAL APPLICATION CIRCUIT 1 VSBY_5V 2 + VCC_5V C1 10µ F GND VCC GND VOUT GND AUX GND 7 + 3 C2 10µF 4 3.3V/500mA 8 VSBY + C3 10µ F 6 5 VAUX_3.3V AIC1531 Dual Input Regulator with Auxiliary Power Switch n ORDERING INFORMATION PIN CONFIGURATION AIC1531CXXX PACKING TYPE TR: TAPE & REEL TB: TUBE PACKAGE TYPE N: PLASTIC DIP S: SMALL OUTLINE DIP-8 SO-8 TOP VIEW VSBY 1 8 GND VCC 2 7 GND VOUT 3 6 GND AUX 4 5 GND Example: AIC1531CSTR à in SO-8 Package & Taping & Reel Packing Type (CN is not available in Tape & Reel packing type.) n ABSOLUTE MAXIMUM RATINGS VCC, VSBY Input Voltage ..................................................................................................7.0V VAUX Input Voltage ...........................................................................................................4.0V VOUT Output Voltage ........................................................................................................5.0V Operating Temperature Range ............................................................................... -40°C~85°C Storage Temperature Range...............................................................................-65°C ~ 150°C 2 AIC1531 n ELECTRICAL CHARACTERISTICS (VIN= 5V, TA=25°C, unless otherwise specified.) PARAMETERS Regulated Output Voltage CONDITIONS 0mA < ILOAD < 500mA Regulated Output Current MIN. TYP. MAX. UNIT 3.135 3.300 3.465 V 500 mA VCC selected Output Voltage Load ILOAD=50mA ~ 500 mA Regulation VSBY selected 20 mV 2 mV ILOAD=50mA ~ 500mA Output Voltage Line Regulation VCC=4.5V~5.5V, ILOAD=5mA VSBY=4.5V~5.5V, ILOAD=5mA VCC Select Voltage VSBY > VSBYDES or VAUX present VCC Deselect Voltage VCC < VCCDES VSBY Select Voltage VAUX present VSBY Deselect Voltage VSBY< VSBYDES Hysteresis Voltage VCC , VSBY are deselected Short Circuit Current VCC/SBY=5V, VOUT =0V VCC Pin Reverse Leakage One supply input taken to ground VSBY Pin Reverse Leakage while the others remain at nominal AUX Pin Reverse Leakage voltage (when VSBY is not present) VSBY Supply Current (when VCC is not present) VAUX Supply Current Ground Current 3.90 4.20 4.50 3.90 4.60 4.60 4.20 0.30 Auxiliary Switch Resistance VCC Supply Current 4.50 120 V V V 200 1000 mΩ mA 5 50 VCC > VCCSEL , ILOAD=0mA 70 300 VCCDES > VCC > VOUT 50 200 VOUT > VCC 10 20 VSBY > VCCSEL , ILOAD=0mA 70 300 VSBYDES > VSBY > VOUT 50 200 VOUT > VSBY 10 20 VCC or VSBY > VOUT 10 100 VCC and VSBY < VOUT 50 400 Both VCC and VSBY are deselected 60 300 VCC/SBY=5V , ILOAD = 0mA 100 500 VCC/SBY=5V , ILOAD = 500mA 100 500 µA µA µA µA µA 3 AIC1531 n TYPICAL PERFORMANCE CHARACTERISTICS VCC VC C VOUT VOUT 500mA 500mA Fig. 1 VCC Cold Start Fig. 2 VC C Full Power Down VSBY VSBY VOUT VOUT 500mA Fig 3. VSBY Cold Start 500mA Fig. 4 VSBY Full Power Down. VAUX VAUX VOUT VOUT 500mA Fig. 5 VAUX Cold Start 500mA Fig. 6 VAUX Full Power Down. 4 AIC1531 n TYPICAL PERFORMANCE CHARACTERISTICS (Continued) V SBY VSBY VCC VCC VOUT VOUT 375mA 375mA Fig. 7 VCC Power Up ( VSBY =5V) Fig. 8 VCC Power down ( VSBY =5V) VCC VCC VOUT VOUT 375mA 375mA Fig. 9 VCC Power Up ( VAUX = 3.3V) Fig. 10 VCC Power Down ( VAUX = 3.3V) IOUT IOUT 5mA→500mA 500mA→5mA VOUT Fig. 11 VCC Load Transient Rising VOUT Fig. 12 VCC Load Transient Falling 5 AIC1531 n TYPICAL PERFORMANCE CHARACTERISTICS (Continued) VCC 5.5V→4.5V VCC 4.5V→5.5V VOUT VOUT 5mA Loading Fig. 13 5mA Loading Fig. 14 VCC Line Transient Rising 3.40 3.35 3.400 100mA 3.375 500mA 3.350 VOUT (V) 3.30 V OUT (V) VC C Line Transient Falling 3.25 3.20 3.325 3.300 3.275 3.15 3.250 3.10 3.05 3.0 3.225 3.200 3.5 4.0 4.5 5.0 0 200 VCC Line Regulation 180 3.280 160 3.275 140 3.270 120 3.260 80 3.255 3.250 60 3.0 3.3 V AUX (V) Load current Fig. 17 VAUX Switch Resistance vs. VAUX 800 3.265 100 2.7 600 Fig. 16 Load Regulation V OUT (V) Resistance (mΩ) Fig. 11 400 Load Current (mA) VCC (V) 3.6 -40 -20 0 20 40 60 80 100 Temperature (°C) Fig. 18 Output Voltage vs. Temperature 6 AIC1531 n BLOCK DIAGRAM n PIN DESCRIPTION PIN 1: VSBY - Standby supply voltage (5V) input for 3.3V regulator when VCC falls below VCCDES. Some NICs that operate in “ Wake-On-LAN” mode get a 5V standby through a cable that connects directly to a specific header on the Motherboard. PIN 2: VCC When only VAUX (3.3V) is present, VOUT voltage comes from VAUX through an internal low impedance switch. PIN 4: AUX - Auxiliary supply voltage (3.3V) input for low impedance switch. PIN 5-8: GND - Negative reference for all voltages. - Primary supply voltage (5V) input for 3.3V regulator. PIN 3: VOUT - 3.3V regulated output voltage when either VCC or V SBY is present. n APPLICATIONS INFORMATION The Requirement for External Capacitors IC as possible. The input capacitor can reduce the The selection of the output capacitor is based on parasitic effect formed by the power supply output two requirements: LDO compensation and the impedance or the trace. A 10µF Tantalum capacitor transition between power sources. During the is a good choice. Additional ceramic capacitor can takeover between sources, the output capacitor be placed close to input and output to reduce the provides the loading. Therefore a larger output high frequency noise. A 0.1µF is recommended. capacitor can improve the transition. And since the output capacitor plays the important role in the The layout and Thermal Considerations compensation of LDO, a 10µF Tantalum capacitor The AIC1531 is housed in a thermally enhanced or larger is recommended. package where the GND pins (Pin5 to Pin8) are integrated to the leadframe. Generally, heat sinks The input capacitor is required to be as close to the are not available for most surface-mounted devices. 7 AIC1531 Instead, they rely on the printed-circuit board to used thermal path. To make sure the thermal provide the thermal path. When the AIC1531 resistance small enough and the shutdown function operates normally, the maximum power dissipation work normally, the thermal resistance between is PD = (VIN − VOUT ) × IOUT = (5 − 3.3) × 0.5 = 0.85W GND pins to GND plane should be as small as possible by means of adding more vias. And the GND plane should be at least 1 square centimeters of copper. At the maximum operation temperature, the thermal resistance seen by the device, or the combination of all the thermal paths, should be 165 − 85 R JA < = 94 °C/W . 0.85 The layout of AIC1531 is shown in Fig.1. In Fig. 2, the thermal resistance RJA is 70.36°C/W where the AIC1531 is mounted on the double-sided PCB and measured under the forced-air thermal chamber. When the device is mounted on a double-sided printed circuit board, the ground plane is the most Fig.19 The layout of AIC1531 2.6 Power Dissipation (W) 2.4 2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0 20 40 60 80 100 Ambient Temperature (°C) Fig.20 The power thermal shutdown dissipation vs. ambient temperature where RJA is 70.36°C/W in the forced-air thermal chamber 8 AIC1531 The Application circuits USB_5V + C1 10µF 22µ H SS12 U1 27K R3 R1 VIN 1 22 + 2 C4 22µF U2 + L1 C9 1µF 3 4 R7 51k 220µF R5 15k 8 ILIM/SD VOUT _3.3V Q1 si2301 C11 D1 1 2 VOUT 7 VIN LBI SW LBO R6 12k 6 3 R8 30K 4 + GND VCC GND VOUT GND AUX C13 10µF 5 SGND VSBY CGND GND 8 7 + 6 5 C5 47 µF AIC1531 AIC1631 Fig.21 The Step Up/Down converter with OR function for dual power system 22µH D1 L1 + SS12 27K R2 R1 VIN U2 U1 1 8 1 ILIM/SD VOUT 7 2 VIN LBI 6 3 SW LBO 5 4 SGND CGND 22 C1 22µ USB_5V + C4 10 µF C2 1µ 2 3 + 4 C3 220µF VOUT_3.3V VSBY GND 8 VCC GND 7 VOUT GND 6 AUX GND 5 + C5 47µF AIC1531 AIC1631 Fig.22 The Step Up converter with OR function for dual power system USB_5V + V OUT_3.3V C4 10µ F U2 1 V IN 2.7~5.5V U1 1 VOUT C1 10µ F 2 2 CAP C3 10µF VIN 5 GND 3 SHDN 6 CAP 4 C2 1µ F 3 4 VSBY GND VCC GND VOUT GND AUX GND 8 7 + 6 5 C5 22µ F AIC1531 AIC1845 Fig. 23 The Step Up/Down converter with OR function for dual power system 9 AIC1531 n PHYSICAL DIMENSIONS l 8 LEAD PLASTIC SO (unit: mm) D SYMBOL MIN MAX A 1.35 1.75 A1 0.10 0.25 B 0.33 0.51 C 0.19 0.25 D 4.80 5.00 E 3.80 4.00 H E e A e A1 C B L 1.27(TYP) H 5.80 6.20 L 0.40 1.27 l 8 LEAD PLASTIC DIP (unit: mm) D E1 E A2 A1 eB e MIN MAX A1 0.381 — A2 2.92 4.96 b 0.35 0.56 C 0.20 0.36 D 9.01 10.16 E 7.62 8.26 E1 6.09 7.12 C L b SYMBOL e 2.54 (TYP) eB — 10.92 L 2.92 3.81 10