19-1376; Rev 1; 12/98 3V to 5V Regulating Charge Pumps for SIM Cards The MAX1686 provides power for dual-voltage subscriber ID module (SIM) cards in portable applications such as GSM cellular phones. Designed to reside in the portable unit (cellular phone handset), the 1MHz charge pump converts a 2.7V to 4.2V input to regulated 5V output. The MAX1686H has a nominal output voltage of 5.0V, while the MAX1686 is set to 4.75V to reduce SIMcard current drain. The charge pump has only 45µA quiescent supply current, which reduces to 3µA when a 3V-capable SIM card is being powered and the charge pump is disabled. An internal input/output shorting switch provides power for 3V SIM cards. The MAX1686/MAX1686H require only three external capacitors around their space-saving, thin (1mm) 8-pin µMAX packages. Features ♦ 2.7V to 4.2V Input Range ♦ 12mA min Charge-Pump Output Current ♦ 45µA Quiescent Supply Current ♦ 0.1µA Supply Current in Shutdown Mode ♦ 5.0V Regulated Charge-Pump Output (MAX1686H) 4.75V Regulated Charge-Pump Output (MAX1686) ♦ Input-Output Shorting Switch for 3V Cards ♦ Small External Components (Uses a 0.047µF, 0.1µF, and a 2.2µF Capacitor) ♦ Output Driven to Ground in Shutdown Mode ♦ Super-Small 8-Pin µMAX Package ♦ Soft-Start and Short-Circuit Protection Applications GSM Cellular Phones PCS Phones Ordering Information Portable POS Terminals Personal Communicators PART TEMP. RANGE MAX1686EUA -40°C to +85°C 8 µMAX MAX1686HEUA -40°C to +85°C 8 µMAX Typical Operating Circuit CXN CXP OUTPUT VIN OR 5V/20mA OUT IN CIN Pin Configuration TOP VIEW CX INPUT 2.7V TO 4.2V PIN-PACKAGE MAX1686 SHDN MAX1686H 3/5 GND PGND COUT 3/5 1 8 OUT SHDN 2 7 CXP IN 3 6 CXN GND 4 5 PGND MAX1686 MAX1686H µMAX ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 1-800-835-8769. MAX1686/MAX1686H General Description MAX1686/MAX1686H 3V to 5V Regulating Charge Pumps for SIM Cards ABSOLUTE MAXIMUM RATINGS IN, OUT, SHDN, 3/5 to GND.....................................-0.3V to +6V CXP to GND..............................................-0.3V to (VOUT + 0.3V) CXN to GND ................................................-0.3V to (VIN + 0.3V) PGND to GND ......................................................-0.3V to + 0.3V OUT Short Circuit to GND ..........................................Continuous IN-to-OUT Current...............................................................50mA Continuous Power Dissipation (TA = +70°C ) 8-Pin µMAX (derate 4.1mW/°C above +70°C) .............330mW Operating Temperature Range MAX1686EUA/MAX1686HEUA........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +165°C Lead Temperature (soldering, 10sec) .............................+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 (VIN = V SHDN = 3.3V, 3/5 = GND, CX = 0.22µF, COUT = 10µF (see Applications Information section to use smaller capacitors), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) CONDITIONS PARAMETER MIN Input Voltage Range 2.7 Input Undervoltage-Lockout Threshold Voltage 0.8 Quiescent Supply Current Charge pump enabled, no load, 3/5 = GND TA = +25°C OUT Output Voltage 45 MAX UNITS 4.2 V 1.6 V 100 150 3 VIN = 3.6V, SHDN = GND VIN = 2.7V to 4.2V, load = 0 to 12mA 1.2 TA = -40°C to +85°C Charge pump disabled, no load, 3/5 = IN Shutdown Supply Current TYP µA 10 0.1 5 µA MAX1686 4.55 4.75 5.25 MAX1686H 4.75 5.00 5.25 V Ω 3/5 = IN VIN IN-to-OUT Switch On-Resistance V3/5 = VIN = 3.0V 2.5 5 OUT Discharge Switch On-Resistance 3/5 = GND or IN, SHDN = GND 80 200 Ω OUT Short-Circuit Current 3/5 = GND or IN 100 200 mA Logic Input Low Voltage SHDN, 3/5 Logic Input High Voltage SHDN, 3/5 Logic Input Leakage Current SHDN, 3/5 = GND or IN Charge-Pump Frequency 20 0.5 · VIN 0.3 · VIN 0.7 · VIN 0.5 · VIN TA = +25°C 800 TA = -40°C to +85°C 700 V V 0.1 1 1000 1200 1300 µA kHz Note 1: Electrical specifications are measured by pulse testing and are guaranteed for a junction temperature within the operating temperature range, unless otherwise noted. Limits are 100% production tested at TA = +25°C. Limits over the entire operating temperature range are guaranteed through correlation using Statistical Quality Control (SQC) methods and are not production tested. 2 _______________________________________________________________________________________ 3V to 5V Regulating Charge Pumps for SIM Cards EFFICIENCY vs. INPUT VOLTAGE (5V MODE) VIN = 3.3V EFFICIENCY (%) 40 30 60 50 40 30 20 20 10 10 1000 0 0 0.1 1 10 10 0.1 0 100 100 1 1 2 3 4 5 0 6 1 2 3 4 INPUT VOLTAGE (V) INPUT VOLTAGE (V) NO-LOAD INPUT CURRENT vs. INPUT VOLTAGE (5V MODE) OUTPUT VOLTAGE vs. LOAD CURRENT (3V MODE) MAX1686 OUTPUT VOLTAGE vs. LOAD CURRENT (5V MODE) 4.80 3.32 MAX1686-06 3.34 MAX1686-04 10,000 6 5 LOAD CURRENT (mA) MAX1686-05 EFFICIENCY (%) VIN = 3.6V ILOAD = 10mA ILOAD = 1mA 70 60 50 80 MAX1686-03 VIN = 2 .7V 70 90 INPUT CURRENT (µA) 80 MAX1686-01 90 NO-LOAD INPUT CURRENT vs. INPUT VOLTAGE (3V MODE) MAX1686-TOC2 EFFICIENCY vs. LOAD CURRENT (5V MODE) 4.79 100 3.30 3.28 3.26 3.24 4.77 4.76 VIN = 3.6V 4.75 VIN = 3 .3V 4.74 VIN = 2.7V 4.73 4.72 10 3.22 4.71 3.20 1 1 2 3 4 5 4.70 0 6 5 10 15 20 25 0.1 1 10 INPUT VOLTAGE (V) LOAD CURRENT (mA) LOAD CURRENT (mA) OUTPUT VOLTAGE vs. INPUT VOLTAGE (3V MODE) OUTPUT VOLTAGE vs. INPUT VOLTAGE (5V MODE) OUTPUT WAVEFORM (ILOAD = 10mA) 6 NO LOAD NO LOAD 4 3 2 MAX1686H 5 OUTPUT VOLTAGE (V) 5 100 MAX1686-09 MAX1686-07 6 MAX1686-08 0 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) INPUT CURRENT (µA) 4.78 1000 MAX1686 4 VOUT (20mV/div) 3 2 1 1 0 0 0 1 2 3 4 INPUT VOLTAGE (V) 5 6 0 1 2 3 4 INPUT VOLTAGE (V) 5 6 2.5µs/div 5V MODE, AC COUPLED, COUT = 10µF 0.1µF _______________________________________________________________________________________ 3 MAX1686/MAX1686H Typical Operating Characteristics (See Typical Operating Circuit, CIN = 0.47µF, CX = 0.22µF, COUT = 10µF, VIN = 3.3V, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (See Typical Operating Circuit, CIN = 0.47µF, CX = 0.22µF, COUT = 10µF, VIN = 3.3V, TA = +25°C, unless otherwise noted.) LINE-TRANSIENT RESPONSE MAX1686-10 MAX1686-11 LOAD-TRANSIENT RESPONSE VIN (500mV/div) MAX1686-12 OUTPUT WAVEFORM (ILOAD = 1mA) ILOAD (10mA/div) VOUT (20mV/div) VOUT (50mV/div) 2.5ms/div VIN = 2.8V to 3.3V, ILOAD = 10mA, 5V MODE, AC COUPLED ILOAD = 0 TO 10mA, 5V MODE, AC COUPLED START-UP WAVEFORM (5V MODE, RL = 500Ω) SHDN (5V/div) MAX1686-15 3V MODE TO 5V MODE WAVEFORM (RL = 500Ω) MAX1686-14 MAX1686-13 START-UP WAVEFORM (3V MODE, RL = 500Ω) SHDN (5V/div) VOUT (50mV/div) 2.5ms/div 25µs/div 5V MODE, AC COUPLED, COUT = 10µF 0.1µF 3/5 (5V/div) VOUT (1V/div) VOUT (1V/div) VOUT (1V/div) 0V 0V 0V 250µs/div SHUTDOWN WAVEFORM (3V MODE, NO LOAD) SHUTDOWN WAVEFORM (5V MODE, NO LOAD) 5V MODE TO 3V MODE WAVEFORM (NO LOAD) SHDN (5V/div) SHDN (5V/div) 0V 3/5 (5V/div) VOUT (1V/div) VOUT (1V/div) VOUT (1V/div) MAX1686-18 250µs/div MAX1686-17 250µs/div MAX1686-16 MAX1686/MAX1686H 3V to 5V Regulating Charge Pumps for SIM Cards 0V 0V 1ms/div 1ms/div 500µs/div RL = 500Ω 4 _______________________________________________________________________________________ 3V to 5V Regulating Charge Pumps for SIM Cards PIN NAME FUNCTION 3V/5V Select Input. When low, the output is regulated at 4.75V for MAX1686, 5.00V for MAX1686H. When high, the output is shorted to the input. 1 3/5 2 SHDN Active-Low Shutdown Input. SHDN = GND is off. Output is actively pulled low in shutdown. 3 IN Supply Input Pin. Can range from 2.7V to 4.2V. Bypass to ground with a ceramic capacitor. 4 GND 5 PGND 6 CXN Negative Terminal of the Charge-Pump Transfer Capacitor 7 CXP Positive Terminal of the Charge-Pump Transfer Capacitor 8 OUT Power Output. Bypass to GND with an output filter capacitor. Ground Pin Power Ground. Connect to GND through a short trace. CX CXN CXP OUT IN S2 S1 PGND OSC EN 1.23V PWROK SS SHDN POWER MANAGEMENT 3/5 DIS MAX1686 MAX1686H GND Figure 1. Functional Diagram _______________Detailed Description The MAX1686/MAX1686H charge pumps provide two modes of operation: 3V mode or 5V mode. The devices consist of an error amplifier, a 1.23V bandgap reference, an internal resistive feedback network, a 1MHz oscillator, high-current MOSFET drivers and switches, and a power-management block as shown in the Functional Diagram (Figure 1). In 3V mode (3/5 = IN), the input is connected to the output through a 2.5Ω switch. In 5V mode (3/5 = GND), the MAX1686’s output voltage is regulated at 4.75V (5.00V for the MAX1686H) with a 2.7V to 4.2V input and can deliver more than 12mA of load current. Designed specifically for compact applications, these regulators require only three small external capacitors. The Skip Mode control scheme provides high efficiency over a wide output current range. The devices offer a shutdown feature which actively discharges the output to ground and reduces the supply current to less than _______________________________________________________________________________________ 5 MAX1686/MAX1686H Pin Description MAX1686/MAX1686H 3V to 5V Regulating Charge Pumps for SIM Cards 1µA. Other features include soft-start, undervoltage lockout, and short-circuit protection. Charge-Pump Control Figure 2 shows an idealized, unregulated charge-pump voltage doubler. The oscillator runs at a 50% duty cycle. During one half of the period, the transfer capacitor (CX) charges to the input voltage. During the other half, the doubler stacks the voltage across CX and the input voltage, and transfers the sum of the two voltages to the output filter capacitor (COUT). The MAX1686 uses Skip Mode control to regulate its output voltage and to achieve good efficiency over a large output current range. When the comparator detects that the output voltage is too low, the 1MHz oscillator is enabled and CX is switched. When the output voltage is above regulation, the oscillator is disabled and CX is connected at the input. In 3V mode (3/5 = IN), the start-up current is limited by the 50Ω series P-channel MOSFET connected between IN and OUT until the output voltage reaches VIN / 2. For VOUT > VIN / 2, RON is reduced to 2.5Ω. With a 500Ω load the device turns on in less than 1.5ms (see Typical Operating Characteristics for graphs of start-up waveforms). Shutdown Mode Driving SHDN low places the device in shutdown mode, which disables the oscillator, the control logic, and the reference. Placing the device in shutdown mode reduces the no-load supply current to less than 1µA; the output is actively discharged through the internal Nchannel FET and disconnected from the input. In normal operation, SHDN is driven high or connected to IN. Applications Information Soft-Start Capacitor Selection In the 5V mode (3/5 = GND), the start-up current is limited by the soft-start control to typically 200mA, independent of the load. Until the output voltage reaches VIN / 2, the input is connected to the output through a 50Ω series P-channel MOSFET and the charge pump is disabled. For V IN / 2 < V OUT < 4.75V (5.00V for MAX1686H) and for a maximum of 2ms the charge pump is active, but RON of the switch S2 is limited to 50Ω. This limits typical current surges associated with charge pumps at start-up. When soft-start is complete, VOUT > 4.75V (5.00V for MAX1686H) or 2ms (whichever occurs first), switch S2’s on-resistance is decreased to minimize losses. The MAX1686 requires only three external capacitors. The capacitor values are closely linked to the output current capability, noise, and switching frequency. The 1MHz oscillator frequency minimizes capacitor size compared to lower-frequency charge pumps. Generally, the transfer capacitor (C X ) will be the smallest, the input capacitor (CIN) will be twice the size of CX, and the output capacitor (COUT) can be from 10 to 50 times CX. The suggested capacitor values are C IN = 0.1µF, C X = 0.047µF, and C OUT = 2.2µF as shown in Figure 3. For input voltages as low as 2.7V, the following values are recommended: CIN = 0.47µF, CX = 0.22µF, and COUT = 10µF. Table 1 lists the perfor- CX CXN CX 0.047µF CXP IN OUT CIN 3 6 7 CXN CXP OUT IN CIN 0.1µF S2 S1 INPUT 2.85V TO 4.2V 2 COUT 3V 5V OSC 1 8 MAX1686 SHDN 3/5 GND 4 PGND 5 GND Figure 2. Unregulated Voltage Doubler 6 Figure 3. Standard Application Circuit _______________________________________________________________________________________ OUTPUT VIN OR 4.75V AT 20mA COUT 2.2µF (CERAMIC) 3V to 5V Regulating Charge Pumps for SIM Cards Table 1. Ripple and Efficiency vs. Input Voltage and Load Current INPUT VOLTAGE (V) LOAD CURRENT (mA) 2.7 1 30 84.3 2.7 10 30 86.2 3.3 1 60 69.5 3.3 10 60 70.5 3.6 1 80 63.2 3.6 10 80 63.8 4.2 1 120 52.3 4.2 10 120 52.1 VOUT RIPPLE EFFICIENCY (mV) (%) Layout Considerations High switching frequencies and large peak currents make PC board layout an important part of design. All capacitors should be soldered close to the IC. Connect ground and power ground through a short, lowimpedance trace. Keep the extra copper on the board and integrate it into ground as a pseudo-ground plane. On multilayer boards, route the star ground using component-side copper fill, then connect it to the internal ground plane using vias. Ensure that the load is connected directly across the output filter capacitor. Table 2. Recommended Surface-Mount Capacitor Manufacturers VALUE (µF) DESCRIPTION MFR. PHONE NUMBER 1 to 47 595D-series tantalum Sprague (603) 224-1961 4.7 to 47 TPS-series tantalum AVX (803) 946-0690 1 to10 267 series tantalum Matsuo (714) 969-2491 0.047 to 2.2 X7R ceramic TDK (847) 390-4373 AVX (803) 946-0690 Chip Information TRANSISTOR COUNT: 840 _______________________________________________________________________________________ 7 MAX1686/MAX1686H mance with different input voltages and an additional small 0.1µF capacitor at the output. The extra 0.1µF capacitor improves start-up capability under full load and reduces output ripple for high input voltages. Table 2 lists the recommended capacitor manufacturers. Low-ESR capacitors, such as surface-mount ceramics, decrease noise and give the best efficiency. Capacitance and ESR variation over temperature need to be taken into consideration for best performance in applications with large operating temperature ranges. For applications where the minimum input voltage is 3V or greater, the flying capacitor, CX, can be decreased to 0.1µF. This provides two benefits: the inrush surge current at start-up is reduced, and the output ripple voltage (especially at high input voltages) is also reduced. 3V to 5V Regulating Charge Pumps for SIM Cards 8LUMAXD.EPS MAX1686/MAX1686H Package Information 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. 8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 1998 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.