19-3671; Rev 0; 5/05 KIT ATION EVALU LE B A IL A AV 200mA Step-Up Converters in 6-Pin SOT23 and TDFN The MAX8569A/MAX8569B low-quiescent-current boost regulators provide up to 200mA at output voltages up to 5.5V from a 1.5V to 5.5V input source. The built-in synchronous rectifier allows for over 90% efficiency while achieving small size and low cost by eliminating the need for an external Schottky diode. The MAX8569A provides an adjustable output while the MAX8569B is fixed at 3.0V or 3.3V. The MAX8569B features a power-on reset output (RST) to signal that the output has reached regulation. All devices connect the battery input to the output during shutdown, allowing the input battery to be used as a backup or real-time clock supply when the converter is off. Applications Medical Diagnostic Equipment Cordless Phones Digital Cameras PC Cards PDAs and Smartphones Local 3.3V or 5V Supply ♦ 1.5V to 5.5V Input Voltage Range ♦ BATT Connected to OUT in Shutdown for Backup Power ♦ Up to 95% Efficiency ♦ 7µA Typical Quiescent Current ♦ <1µA Shutdown Supply Current ♦ Internal Synchronous Rectifier ♦ 750mA Switch Current Limit ♦ RST Output (MAX8569B) ♦ Adjustable Output Voltage (MAX8569A) ♦ Fixed 3.0V or 3.3V Output Voltage (MAX8569B) Ordering Information LX 3.3V, 200mA OUTPUT OUT BATT POWER-ON RESET RST SHDN PART TEMP RANGE PIN-PACKAGE MAX8569AEUT-T* -40°C to +85°C 6 SOT23-6 (U6FH-6) MAX8569AETT+ -40°C to +85°C 6 TDFN 3mm x 3mm (T633-1) MAX8569BEUT-T* -40°C to +85°C 6 SOT23-6 (U6FH-6) MAX8569BETT+ -40°C to +85°C 6 TDFN 3mm x 3mm (T633-1) MAX8569BETT30+ -40°C to +85°C 6 TDFN 3mm x 3mm (T633-1) MAX8569B ON OFF ♦ Over 200mA Available Output Current Battery Backup Typical Operating Circuit 2V INPUT Features GND *Future product—contact factory for availability. Selector Guide appears at end of data sheet. +Denotes lead-free packaging. OUT LX TOP VIEW FB (RST) Pin Configurations 6 5 4 TOP VIEW SHDN 1 BATT 2 MAX8569A (MAX8569B) 6 FB (RST) MAX8569A (MAX8569B) 4 LX ( ) ARE FOR THE MAX8569B 2 3 GND SHDN 1 BATT GND 3 + 5 OUT SOT23 TDFN + DENOTES LEAD-FREE PACKAGING ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX8569A/MAX8569B General Description MAX8569A/MAX8569B 200mA Step-Up Converters in 6-Pin SOT23 and TDFN ABSOLUTE MAXIMUM RATINGS BATT, LX, OUT, FB, RST to GND .............................-0.3V to +6V SHDN to GND...........................................-0.3V to (VOUT + 0.3V) LX Current ....................................................................1.5A Peak Continuous Power Dissipation (TA = +70°C) 6-Pin SOT23 (derate 9.1mW/°C above +70°C)............727mW 6-Pin TDFN 3mm x 3mm (derate 18.2mW/°C above +70°C) .............................1454mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VSHDN = VOUT = 3.3V, VBATT = 2.0V, TA = -40°C to +85°C. Typical values are at TA = +25°C, unless otherwise noted.) (Note 1) PARAMETER CONDITIONS TYP MAX UNITS 5.5 V TA = +25°C 1.22 1.5 TA = -40°C to +85°C 1.24 Battery Input Range Startup Voltage 1.5 RLOAD = 2.6kΩ MAX8569A Output Voltage MIN MAX8569BETT30 MAX8569B 2.0 TA = +25°C 2.94 TA = -40°C to +85°C 2.925 TA = +25°C 3.233 TA = -40°C to +85°C 3.217 TA = +25°C 1.208 TA = -40°C to +85°C 1.203 V 5.5 3.0 3.06 3.075 3.300 V 3.366 3.373 1.228 1.248 Feedback Threshold MAX8569A Feedback Bias Current MAX8569A, VFB = 1.27V n-Channel On-Resistance ILX = 100mA 0.3 0.7 Ω p-Channel On-Resistance ILX = 100mA 0.3 0.9 Ω 750 920 TA = +25°C 1.253 3.5 TA = -40°C to +85°C 20 4 V nA TA = +25°C 650 TA = -40°C to +85°C 600 Switch Maximum On-Time VOUT = 2.8V 3.5 5 Synchronous Rectifier ZeroCrossing Current TA = +25°C 3 25 TA = -40°C to +85°C 0 OUT Quiescent Current VOUT = 3.5V, VFB = 1.3V (Note 2) 4 OUT Shutdown Current VOUT = 3.5V, VSHDN = VFB = 0V 0.05 1 µA BATT Quiescent Current VOUT = 3.5V, VFB = 1.3V (Note 3) 3 10 µA BATT Shutdown Current VOUT = 3.5V, VSHDN = 0V 0.01 1 µA 0.3 V n-Channel Switch Current Limit 975 50 60 SHDN Logic-Low 2 6.5 _______________________________________________________________________________________ 10 mA µs mA µA 200mA Step-Up Converters in 6-Pin SOT23 and TDFN (VSHDN = VOUT = 3.3V, VBATT = 2.0V, TA = -40°C to +85°C. Typical values are at TA = +25°C, unless otherwise noted.) (Note 1) PARAMETER CONDITIONS Rising edge, 100mV hysteresis (typ), VOUT = 2.8V SHDN Threshold SHDN Input Bias Current VOUT = 5.5V RST Low Voltage IRST = 1mA, VOUT = 2.5V RST Leakage Current VRST = 5.5V RST Threshold Relative to OUT, 3.3V for MAX8569B, 3.0V for MAX8569BETT30 LX Leakage Current VOUT = 5.5V MIN TYP MAX TA = +25°C 1.185 1.228 1.271 TA = -40°C to +85°C 1.170 UNITS V 1.286 TA = +25°C 13 TA = -40°C to +85°C 13 TA = +25°C 0.1 100 0.2 TA = -40°C to +85°C 100 1 TA = +25°C 85 90 95 TA = -40°C to +85°C 85 90 97 1 150 nA V nA % TA = +25°C TA = -40°C to +85°C 150 nA Maximum Load Current VBATT = 2V, VOUT = 3.3V 200 mA Efficiency VBATT = 2V, VOUT = 3.3V, Figures 1 or 2, ILOAD = 40mA 88 % Note 1: Specifications to -40°C are guaranteed by design and not production tested. Note 2: Supply current into OUT. This current is drawn from the source battery, but is reduced in value according to the step-up ratio and efficiency. Note 3: Does not include switching losses and output quiescent current. See the Input Current and Output Voltage vs. Input Voltage (On, 330Ω) graph in the Typical Operating Characteristics for operating quiescent current. _______________________________________________________________________________________ 3 MAX8569A/MAX8569B ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (Circuit of Figure 2, VOUT = 3.3V, VBATT = +2V, TA = +25°C, circuit of Figure 1, TA = +25°C, unless otherwise noted.) EFFICIENCY vs. LOAD CURRENT VOUT = 5V EFFICIENCY vs. LOAD CURRENT VOUT = 3.3V VIN = 4.2V VIN = 2V EFFICIENCY (%) VIN = 2.5V 85 80 75 75 65 65 100 10 1000 1 10 100 1000 LOAD CURRENT (mA) LOAD CURRENT (mA) EFFICIENCY vs. LOAD CURRENT VOUT = 2.5V MAXIMUM OUTPUT CURRENT vs. BATTERY VOLTAGE MAX8569 toc03 100 95 90 85 VIN = 2V 80 75 VIN = 1.5V 70 65 600 MAXIMUM OUTPUT CURRENT (mA) 1 VOUT = 2.5V 500 VOUT = 3.3V 400 300 VOUT = 5V 200 100 0 60 1 100 10 1.5 1000 2.5 3.5 4.5 5.5 LOAD CURRENT (mA) BATTERY VOLTAGE (V) STARTUP VOLTAGE vs. LOAD RESISTANCE OUTPUT VOLTAGE AND INPUT CURRENT vs. INPUT VOLTAGE (SHUTDOWN, NO LOAD) 1.32 5 OUTPUT VOLTAGE (V) 1.30 1.28 1.26 1.24 MAX8569 toc06 6 MAX8569 toc05 1.34 1.20 5 VOUT 4 4 3 3 2 2 IBATT 1 1.22 1 0 10 100 1k RLOAD (Ω) 10k 6 0 0 1 2 3 4 5 BATTERY VOLTAGE (V) _______________________________________________________________________________________ 6 BATTERY CURRENT (µA) EFFICIENCY (%) VIN = 1.5V 80 70 70 4 85 MAX8569 toc04 EFFICIENCY (%) VIN = 2.5V 90 VIN = 3.3V 90 MAX8569 toc02 95 95 MAX8569 toc01 100 STARTUP VOLTAGE (V) MAX8569A/MAX8569B 200mA Step-Up Converters in 6-Pin SOT23 and TDFN 200mA Step-Up Converters in 6-Pin SOT23 and TDFN OUTPUT VOLTAGE AND INPUT CURRENT vs. INPUT VOLTAGE (ON, 330Ω) MAX8569 toc07 4.0 5 VOUT 4 4 3 3 2 2 IBATT 1 1 0 0 0 1 2 3 4 5 3.5 3.0 3.0 2.5 2.5 2.0 2.0 IBATT 1.5 1.5 1.0 1.0 0.5 0.5 0 6 0 0 1 2 3 4 5 6 BATTERY VOLTAGE (V) OUTPUT VOLTAGE AND INPUT CURRENT vs. INPUT VOLTAGE (ON, 16Ω LOAD) MAX8569 toc09 4.0 ON/OFF RESPONSE (RLOAD = 33Ω) MAX8569 toc10 4.5 4.0 VOUT 3.5 3.5 3.0 3.0 2.5 2.5 2.0 2.0 IBATT 1.5 1.5 1.0 1.0 0.5 0.5 0 BATTERY CURRENT (µA) OUTPUT VOLTAGE (V) 4.5 4.0 VOUT 3.5 BATTERY VOLTAGE (V) 4.5 MAX8569 toc08 4.5 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 5 6 BATTERY CURRENT (µA) 6 BATTERY CURRENT (µA) OUTPUT VOLTAGE AND INPUT CURRENT vs. INPUT VOLTAGE (SHUTDOWN, 200mA LOAD) VOUT 1V/div VIN 1V/div 0 0 1 2 3 4 5 6 100µs/div BATTERY VOLTAGE (V) LOAD TRANSIENT LINE TRANSIENT MAX8569 toc11 MAX8569 toc12 100mV/div VOUT (AC-COUPLED) VOUT (AC-COUPLED) 100mV/div 2.5V 2V 200mA IOUT VIN 20mA 100µs/div 100ms/div _______________________________________________________________________________________ 5 MAX8569A/MAX8569B Typical Operating Characteristics (continued) (Circuit of Figure 2, VOUT = 3.3V, VBATT = +2V, TA = +25°C, circuit of Figure 1, TA = +25°C, unless otherwise noted.) MAX8569A/MAX8569B 200mA Step-Up Converters in 6-Pin SOT23 and TDFN Typical Operating Characteristics (continued) (Circuit of Figure 2, VOUT = 3.3V, VBATT = +2V, TA = +25°C, circuit of Figure 1, TA = +25°C, unless otherwise noted.) SHUTDOWN RESPONSE (RLOAD = 33Ω) SWITCHING WAVEFORMS (RLOAD = 33Ω) MAX8569 toc14 MAX8569 toc13 VOUT (AC-COUPLED) 100mV/div 3.3V VOUT 2V VLX 2V/div IL VSHDN 500mA/div 2V/div 10µs/div 100µs/div Pin Description PIN 6 NAME FUNCTION 1 SHDN Shutdown Input. Drive SHDN low to place the MAX8569 in shutdown mode. SHDN can be used for a low-battery cutoff (1.228V threshold). See the Low-Battery Cutoff section for details. Drive SHDN high for normal operation. 2 2 BATT Battery Voltage Connection. Connect BATT to a 1.5V to 5.5V supply. Bypass BATT to GND with a 10µF or larger ceramic capacitor. 3 3 GND Ground 4 4 LX Inductor Connection. Connect the switched side of the inductor to LX. During shutdown, LX is connected to OUT. 5 5 OUT Output Voltage. Bypass OUT to GND with a 10µF or larger ceramic capacitor. During shutdown, OUT is connected to LX. OUT is also the bootstrapped supply input for the IC. 6 — FB Feedback Input. Connect FB to the center tap of an external resistor-divider from OUT to GND to set the output voltage. VFB regulates to 1.228V. — 6 RST Reset Output. RST is an open-drain output that goes high impedance when the output voltage rises above 90% of the nominal regulation voltage. RST pulls low when the output is below 90% of the nominal regulation voltage. RST is high impedance during shutdown. — — EP MAX8569A MAX8569B 1 Exposed Paddle (TDFN Package Only). Connect to the PC board ground plane for increased thermal performance. _______________________________________________________________________________________ 200mA Step-Up Converters in 6-Pin SOT23 and TDFN The MAX8569A and MAX8569B compact high-efficiency step-up converters feature low-quiescent supply current to ensure the highest possible efficiency over a wide load range. With a minimum 1.5V input voltage, these devices are well suited for applications with two alkaline cells, two nickel-metal-hydride (NiMH) cells, or one lithium-ion (Li+) cell. When SHDN is low, the output is connected to the battery through the inductor and an internal p-channel MOSFET. This allows the input battery to be used as a backup or real-time clock supply when the converter is off by eliminating the voltage drop across the MOSFET body diode. These devices are ideal for low-power applications where a small footprint is critical. The internal synchronous rectifier improves efficiency significantly and reduces size and cost by eliminating the need for an external Schottky diode. Applications Information Shutdown Drive SHDN low to shut down the MAX8569A/ MAX8569B and reduce the input current to less than 1µA. During shutdown, the battery input is connected to the output through the inductor and the internal synchronous rectifier. This allows the input battery (rather than a separate backup battery) to provide backup power for devices such as an idled microcontroller, SRAM, or real-time clock, without the usual diode forward drop. Drive SHDN to VOUT (logic-high) to enable the IC for normal operation. Control Scheme The MAX8569A/MAX8569B feature a current-limited control scheme that provides ultra-low quiescent current and high efficiency over a wide output current range. The switching cycles are not controlled by an oscillator. 2 1.5V TO 3V INPUT L1 10µH C1 10µF 4 5 OUT BATT MAX8569A LX 1 C2 0.01µF R2 1MΩ C3 22µF 6 FB R1 220kΩ 3.3V OUTPUT R3 168kΩ R4 100kΩ SHDN GND 3 Figure 1. Typical Application Circuit for MAX8569A 2 L1 10µH 1.5V TO 3V INPUT C1 10µF 4 OUT BATT LX C3 22µF MAX8569B RST ON OFF 1 5 6 3.3V OUTPUT R1 100kΩ RESET OUTPUT SHDN GND 3 Figure 2. Typical Application Circuit for MAX8569B _______________________________________________________________________________________ 7 MAX8569A/MAX8569B Instead, switch on-time is terminated when the inductor current reaches the 780mA (typ) n-channel current limit, or when the 5µs maximum n-channel switch on-time is reached. Following each on-cycle, the synchronous rectifier turns on, shunts the MOSFET body diode, and the inductor current ramps to zero before another cycle begins. The next cycle occurs when the error comparator senses that the output has fallen below the regulation threshold. Detailed Description MAX8569A/MAX8569B 200mA Step-Up Converters in 6-Pin SOT23 and TDFN Low-Battery Cutoff The SHDN trip threshold of the MAX8569A/MAX8569B can be used as an input voltage detector that disables the IC when the battery voltage falls to a set level. The SHDN trip threshold is 1.228V. Use a resistor-divider to set the battery-detection voltage (R1 and R2 in Figure 1). Select R2 between 100kΩ and 1MΩ to minimize battery drain. Calculate R1 as follows: R1 = R2 x ((VOFF / V SHDN) - 1) where VOFF is the battery voltage at which the part shuts down and V SHDN = 1.228V. Note that input ripple can sometimes cause false shutdowns. To minimize the effect of ripple, connect a low-value capacitor (C2) from SHDN to GND to filter out input noise. Select a C2 value so the R1, C2 time constant is above 2ms. Power-On Reset (RST, MAX8569B) The MAX8569B provides a power-on reset output (RST) that goes high impedance when the output reaches 90% of its regulation point. RST pulls low when the output is below 90% of the regulation point. Connect a 100kΩ to 1MΩ pullup resistor from RST to OUT to provide a logic control signal for a microprocessor. Connect RST to GND when the reset function is not used. Setting the Output Voltage (MAX8569A) The output of the MAX8569A is adjustable from 2V to 5.5V. Connect a resistor-divider from the output to ground with FB connected to the center tap to set the desired output voltage (R3 and R4, Figure 1). Select R4 between 100kΩ and 1MΩ. R3 is then calculated as follows: R3 = R4 x ((VOUT / VFB) - 1) where RL is the inductor series resistance and RNCH is the RDS(ON) of the internal n-channel MOSFET (0.3Ω typ). Capacitor Selection Choose an output capacitor to achieve the desired output ripple percentage. COUT > (0.5 x L x 0.780A2) / (r% x VOUT2) where L is the inductor value and r is the desired output ripple in %. A 22µF ceramic capacitor is a good starting value. The input capacitor reduces the peak current drawn from the battery and can be the same value as the output capacitor. A larger input capacitor can be used to further reduce the input ripple and improve efficiency. PC Board Layout and Grounding Careful printed circuit layout is important for minimizing ground bounce and noise. Keep the IC’s GND pin and the ground leads of the input- and output-filter capacitors less than 0.2in (5mm) apart. In addition, keep all connections to the FB and LX pins as short as possible. In particular, when using external feedback resistors, locate them as close to FB as possible. To maximize output power and efficiency and minimize output ripple voltage, use a ground plane and solder the IC’s GND directly to the ground plane. A sample layout is available in the MAX8569A/MAX8569B evaluation kit to speed designs. Chip Information PROCESS: BiCMOS where VOUT is the desired output voltage and VFB is 1.228V. Inductor Selection The control scheme of the MAX8569A/MAX8569B permits flexibility in choosing an inductor. A 10µH inductor performs well for most applications, but values from 4.7µH to 100µH can be used as well. Small inductance values typically offer smaller physical size. Output power is reduced when the inductance is large enough to prevent the maximum current limit (780mA) from being reached before the maximum on-time (5µs) expires. For maximum output current, choose L so that: VBATT(MAX) × 1µs 0.78A IOUT(MAX) = 8 < L < Selector Guide OUTPUT VOLTAGE PINPACKAGE TOP MARK Adjustable SOT23-6 ABWK MAX8569BEUT Fixed 3.3V SOT23-6 ABWL MAX8569AETT Adjustable TDFN AJN MAX8569BETT Fixed 3.3V TDFN AJO MAX8569BETT30 Fixed 3.0V TDFN AJP PART MAX8569AEUT VBATT(MIN) × 5µs 0.78A 0.78A 0.78A × VBATT(MIN) − × (RNCH + RL ) 2 2 VOUT _______________________________________________________________________________________ 200mA Step-Up Converters in 6-Pin SOT23 and TDFN 6, 8, &10L, DFN THIN.EPS D2 D A2 PIN 1 ID N 0.35x0.35 b PIN 1 INDEX AREA E [(N/2)-1] x e REF. E2 DETAIL A e k A1 CL CL A L L e e PACKAGE OUTLINE, 6,8,10 & 14L, TDFN, EXPOSED PAD, 3x3x0.80 mm -DRAWING NOT TO SCALE- 21-0137 G 1 2 _______________________________________________________________________________________ 9 MAX8569A/MAX8569B Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.) MAX8569A/MAX8569B 200mA Step-Up Converters in 6-Pin SOT23 and TDFN Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.) COMMON DIMENSIONS MIN. MAX. D 0.70 2.90 0.80 3.10 E A1 2.90 0.00 3.10 0.05 L k 0.20 0.40 0.25 MIN. A2 0.20 REF. SYMBOL A PACKAGE VARIATIONS PKG. CODE N D2 E2 e JEDEC SPEC b [(N/2)-1] x e DOWNBONDS ALLOWED T633-1 6 1.50–0.10 2.30–0.10 0.95 BSC MO229 / WEEA 0.40–0.05 1.90 REF NO T633-2 6 1.50–0.10 2.30–0.10 0.95 BSC MO229 / WEEA 0.40–0.05 1.90 REF NO T833-1 8 1.50–0.10 2.30–0.10 0.65 BSC MO229 / WEEC 0.30–0.05 1.95 REF NO T833-2 8 1.50–0.10 2.30–0.10 0.65 BSC MO229 / WEEC 0.30–0.05 1.95 REF NO T833-3 8 1.50–0.10 2.30–0.10 0.65 BSC MO229 / WEEC 0.30–0.05 1.95 REF YES T1033-1 10 1.50–0.10 2.30–0.10 0.50 BSC MO229 / WEED-3 0.25–0.05 2.00 REF NO T1433-1 14 1.70–0.10 2.30–0.10 0.40 BSC ---- 0.20–0.05 2.40 REF YES T1433-2 14 1.70–0.10 2.30–0.10 0.40 BSC ---- 0.20–0.05 2.40 REF NO PACKAGE OUTLINE, 6,8,10 & 14L, TDFN, EXPOSED PAD, 3x3x0.80 mm -DRAWING NOT TO SCALE- 10 21-0137 ______________________________________________________________________________________ G 2 2 200mA Step-Up Converters in 6-Pin SOT23 and TDFN 6LSOT.EPS Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 11 © 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc. MAX8569A/MAX8569B Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)