L6932 HIGH PERFORMANCE 2A ULDO LINEAR REGULATOR ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 2V TO 14V INPUT VOLTAGE RANGE 200mΩ Rdson MAX. 200µA QUIESCENT CURRENT AT ANY LOAD EXCELLENT LOAD AND LINE REGULATION 1.5V, 1.8V AND 2.5V FIXED VOLTAGE ADJUSTABLE FROM 1.2V TO 5V (L6932D1.2) 1% VOLTAGE REGULATION ACCURACY SHORT CIRCUIT PROTECTION THERMAL SHUT DOWN SO-8 (4+4) PACKAGE APPLICATIONS ■ MOTHERBOARDS SO-8 (4+4) ORDERING NUMBERS: L6932D1.2 (SO-8) L6932D1.2TR (T&R) L6932D1.5 (SO-8) L6932D1.5TR (T&R) L6932D1.8 (SO-8) L6932D1.8TR (T&R) L6932D2.5 (SO-8) L6932D2.5TR (T&R) Mosfet, can be usefull for the DC-DC conversion between 2.5V and 1.5V at 2A in portable applications reducing the power dissipation. ■ MOBILE PC ■ HAND-HELD INSTRUMENTS ■ PCMCIA CARDS ■ PROCESSORS I/O ■ CHIPSET AND RAM SUPPLY L6932 is available in 1.5V, 1.8V, 2.5V and adj version from 1.2V and ensure a voltage regulation accuracy of 1%. DESCRIPTION The L6932 Ultra Low Drop Output linear regulator operates from 2V to 14V and is able to support 2A. Designed with an internal 50mΩ N-channel The current limit is fixed at 2.5A to control the current in short circuit condition within ±8%. The current is sensed in the power mos in order to limit the power dissipation. The device is also provided of a thermal shut down that limits the internal temperature at 150°C with an histeresys of 20°C. L6932 provides the Enable and the Power good functions. TYPICAL OPERATING CIRCUIT VIN IN 3 2 VOUT OUT 1.5V-1.8V-2.5V 2V to 14V L6932D C1 4 5,6,7,8 PGOOD C2 1 GND EN VIN IN 4 2 VOUT OUT 1.2V to 5V 2V to 14V R1 L6932D C1 3 5,6,7,8 ADJ C2 1 R2 GND EN December 2005 Rev. 9 1/11 L6932 PIN CONNECTIONS EN 1 8 GND EN 1 8 GND IN 2 7 GND IN 2 7 GND ADJ 3 6 GND OUT 3 6 GND OUT 4 5 GND PGOOD 4 5 GND L6932D1.2 L6932D1.5 L6932D1.8 L6932D2.5 PIN FUNCTION N° L6232D 1.5/1.8/ 2.5 L6232D 1.2 Description 1 EN Enables the device if connected to Vin and disables the device if forced to gnd. 2 IN Supply voltage. This pin is connected to the drain of the internal N-mos. Connect this pin to a capacitor larger than 10µF. ADJ – Connecting this pin to a voltage divider it is possible to programme the output voltage between 1.2V and 5V. – OUT Regulated output voltage. This pin is connected to the source of the internal N-mos. Connect this pin to a capacitor of 10µF. OUT – Regulated output voltage. This pin is connected to the source of the internal N-mos. Connect this pin to a capacitor of 10µF. 3 4 – 5, 6, 7, 8 PGOOD Power good output. The pin is open drain and detects the output voltage. It is forced low if the output voltage is lower than 90% of the programmed voltage. GND Ground pin. ABSOLUTE MAXIMUM RATINGS Symbol Vin Parameter VIN and Pgood EN, OUT and ADJ Value Unit 14.5 V -0.3 to (Vin +0.3) V Value Unit 62 (*) °C/W 150 °C -65 to 150 °C THERMAL DATA Symbol Rth J-amb Parameter Thermal Resistance Junction to Ambient Tmax Maximum Junction Temperature Tstg Storage Temperature Range (*) Measured on Demoboard with about 4 cm2 of dissipating area 2 Oz. 2/11 L6932 BLOCK DIAGRAM (Referred to the Fixed Voltage version) IN CHARGE PUMP VREF REFERENCE VREF=1.25V EN ENABLE CURRENT LIMIT DRIVER + ERROR AMPL. OUT THERMAL SENSOR PG 0.9 VREF + GND D99IN1100 ELECTRICAL CHARACTERISTCS (Tj = 25°C, VIN = 5V unless otherwise specified) (*) Specification referred to Tj from -25°C to 125°C. Symbol Parameter Test Condition Min. Max. Unit 14 V 1.2 1.212 V 1.485 1.5 1.515 V 1.782 1.8 1.818 V 2.475 2.5 2.525 V 5 mV Vin = 3.3V ±10%; Io = 10mA 5 mV Vin = 5V ±10%; Vin Operating Supply Voltage Vo Output voltage L6932D1.2 Io = 0.1A; Vin = 3.3V 1.188 Output voltage L6932D1.5 Io = 0.1A; Vin = 3.3V Output voltage L6932D1.8 Io = 0.1A; Vin = 3.3V Output voltage L6932D2.5 Io = 0.1A; Vin = 3.3V L6932D1.2 Line Regulation Vin = 2.5V ±10%; Io = 10mA L6932D1.5 Line Regulation L6932D1.8 Line Regulation L6932D2.5 Line Regulation Rdson Typ. 2 Io = 10mA 5 mV Vin = 2.5V ±10%; Io = 10mA 5 mV Vin = 3.3V ±10%; Io = 10mA 5 mV Vin = 5V ±10%; Io = 10mA 5 mV Vin = 2.5V ±10%; Io = 10mA 5 mV Vin = 3.3V ±10%; Io = 10mA 5 mV Vin = 5V ±10%; Io = 10mA 5 mV Vin = 3.3V ±10%; Io = 10mA 5 mV Vin = 5V ±10%; 5 mV L6932D1.2 Load Regulation Vin = 3.3V; 0.1A < Io < 2A 15 mV L6932D1.5 Load Regulation Vin = 3.3V; 0.1A < Io < 2A 15 mV L6932D1.8 Load Regulation Vin = 3.3V; 0.1A < Io < 2A 15 mV L6932D2.5 Load Regulation Vin = 3.3V; 0.1A < Io < 2A 15 mV 200 mΩ Drain Source ON resistance Io = 10mA 3/11 L6932 ELECTRICAL CHARACTERISTCS (continued) Symbol Parameter Iocc Test Condition Current limiting Iq Quiescent current Ish Shutdown current 2V < Vin < 14V Ripple Rejection f = 120Hz, Io = 1A Vin = 5V, ∆Vin = 2Vpp Ven Typ. Max. Unit 2.3 2.5 2.7 A 0.2 0.4 mA 25 µA * EN Input Threshold Pgood threshold Min. 60 75 0.5 0.65 Vo rise Pgood Hysteresis Ipgood =1mA Pgood saturation Figure 1. Output Voltage vs. Junction Temperature (L6932D1.2) dB 0.8 V 90 %Vo 10 %Vo 0.2 0.4 V Figure 3. Output Voltage vs. Junction Temperature (L6932D2.5) 1.213 2.520 1.212 2.515 1.212 2.510 1.211 V V 1.211 2.505 1.210 2.500 1.210 1.209 -60 -40 -20 0 20 40 60 80 2.495 100 120 140 160 -60 -40 -20 0 20 Temp [°C] 40 60 80 100 120 140 160 Temp [°C] Figure 2. Output Voltage vs. Junction Temperature (L6932D1.8) Figure 4. Quiescent Current vs. Junction Temperature 310 1.808 300 1.804 Vin=5V 290 1.800 Iq 280 V 1.796 (uA) 270 1.792 260 1.788 -60 -40 -20 4/11 0 20 40 60 80 Temp [°C] 100 120 140 160 250 -40 -20 0 20 40 60 Temp [°C ] 80 100 120 140 L6932 Figure 5. Shutdown Current vs. Junction TemperatureAPPLICATION INFORMATIONS 7.5 7 6.5 Ishdn Vin=5V 6 (uA) 5.5 5 4.5 4 -40 -20 0 20 40 60 80 100 120 140 Temp [°C ] APPLICATION CIRCUIT In figure 6 the schematic circuit of the demoboards are shown. Figure 6. Demoboards Schematic Circuit VIN VOUT OUT IN 2 EN 3 L6932D1.5 L6932D1.8 L6932D2.5 1 C1 6 5 7 4 PGOOD C2 8 GND VIN IN 4 2 VOUT OUT 1.2V to 5V EN R1 L6932D1.2 1 C1 3 6 5 7 ADJ C2 VOUT = 8 R2 GND 1.2 × (R1+ R2) R2 COMPONENT LIST Fixed version Reference Part Number Description Manufacturer C1 C34Y5U1E106Z 10uF, 25V TOKIN C2 C34Y5U1E106Z 10uF, 25V TOKIN 5/11 L6932 Figure 7. Demoboard Layout (Fixed Version) Adjustable version Reference Part Number Description Manufacturer C1 C34Y5U1E106Z 10uF, 25V TOKIN C2 C34Y5U1E106Z 10uF, 25V TOKIN R1 5.6K, 1%, 0.25W Neohm R2 3.3K, 1%, 0.25W Neohm Figure 8. Demoboard Layout (Adjustable Version) COMPONENTS SELECTION Input Capacitor The input capacitor value depends on a lot of factors such as load transient requirements, input source (battery or DC/DC converter) and its distance from the input cap. Usually a 47µF is enough for any application but a much lower value can be sufficient in many cases. Output Capacitor The output capacitor choice depends basically on the load transient requirements. Tantalum, Speciality Polimer, POSCAP and aluminum capacitors are good and offer very low ESR values. 6/11 L6932 Multilayer ceramic caps have the lowest ESR and can be required for particular applications. Nevertheless in several applications they are ok, the loop stability issue has to be considered (see loop stability section). Below a list of some suggested capacitor manufacturers. Manufacturer Type Cap Value (µF) Rated Voltage (V) PANASONIC CERAMIC 1 to 47 4 to 16 TAYO YUDEN CERAMIC 1 to 47 4 to 16 TDK CERAMIC 1 to 47 4 to 16 TOKIN CERAMIC 1 to 47 4 to 16 SANYO POSCAP 1 to 47 4 to 16 PANASONIC SP 1 to 47 4 to 16 KEMET TANTALUM 1 to 47 4 to 16 Loop Stability The stability of the loop is affected by the zero introduced by the output capacitor. The time constant of the zero is given by: T = ESR ⋅ C OUT 1 F ZERO = -------------------------------------------2π ⋅ ESR ⋅ C OUT This zero helps to increase the phase margin of the loop until the time constant is higher than some hundreds of nsec, depending also on the output voltage and current. So, using very low ESR ceramic capacitors could produce oscillations at the output, in particular when regulating high output voltages (adjustable version). To solve this issue is sufficient to add a small capacitor (e.g. 1nF to 10nF) in parallel to the high side resistor of the external divider, as shown in figure 9. Figure 9. Compensation Network VIN=2V TO 14V IN OUT 2 R1 L6932D1.2 EN C1 VOUT=1.2V TO 5V UP to 2A 4 C3 ADJ 1 5 6 GND 7 3 8 C2 R2 Thermal Considerations Since the device is housed in a small SO(4+2+2) package the thermal issue can be the bottleneck of many applications. The power dissipated by the device is given by: PDISS = (VIN - VOUT) · IOUT 7/11 L6932 The thermal resistance junction to ambient of the demoboard is approximately 62°C/W. This mean that, considering an ambient temperature of 60°C and a maximum junction temperature of 150°C, the maximum power that the device can handle is 1.5W. This means that the device is able to deliver a DC output current of 2A only with a very low dropout. In many applications, high output current pulses are required. If their duration is shorter than the thermal constant time of the board, the thermal impedance (not the thermal resistance) has to be considered. In figure 10 the thermal impedance versus the duration of the current pulse for the SO(4+2+2) mounted on board is shown. Figure 10. Thermal Impedance Considering a pulse duration of 1sec, the thermal impedance is close to 20°C/W, allowing much bigger power dissipated. Example: Vin = 3.3V Vout = 1.8V Iout = 2A Pulse Duration = 1sec The power dissipated by the device is: PDISS = (VIN - VOUT) · IOUT = 1.5 · 2 3W Considering a thermal impedance of 20°C/W, the maximum junction temperature will be: TJ = TA + ZTHJA · PDISS = 60 + 60 = 120°C Obviously, with pulse durations longer than approximately 10sec the thermal impedance is very close to the thermal resistance (60°C/W to 70°C/W). 8/11 L6932 Figure 11. SO-8 Mechanical Data & Package Dimensions mm inch DIM. MIN. TYP. MAX. MIN. TYP. MAX. A 1.35 1.75 0.053 0.069 A1 0.10 0.25 0.004 0.010 A2 1.10 1.65 0.043 0.065 B 0.33 0.51 0.013 0.020 C 0.19 0.25 0.007 0.010 D (1) 4.80 5.00 0.189 0.197 E 3.80 4.00 0.15 0.157 e 1.27 0.050 H 5.80 6.20 0.228 0.244 h 0.25 0.50 0.010 0.020 L 0.40 1.27 0.016 0.050 k ddd OUTLINE AND MECHANICAL DATA 0˚ (min.), 8˚ (max.) 0.10 0.004 Note: (1) Dimensions D does not include mold flash, protrusions or gate burrs. Mold flash, potrusions or gate burrs shall not exceed 0.15mm (.006inch) in total (both side). SO-8 0016023 C 9/11 L6932 Table 1. Revision History Date Revision February 2003 8 First Issue December 2005 9 Added new Ordering Numbers: L6932D1.5 & L6932D1.5TR. 10/11 Description of Changes L6932 Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners © 2005 STMicroelectronics - All rights reserved STMicroelectronics group of companies Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America www.st.com 11/11