19-0227: Rev 2: 5/96 General Description The MAX619 step-up charge-pump DC-DC converter delivers a regulated 5V +4% output at 50mA over tem- perature. The input voltage range is 2V to 3.6V (two battery cells). The complete MAX619 circuit fits into less than 0.1in? of board space because it requires only four external capacitors: two 0.22uF flying capacitors, and 10F capacitors at the input and output. Low operating supply current (150A max) and low shutdown supply current (1A max) make this device ideal for small, portable, and battery-powered applica- tions. When shut down, the load is disconnected from the input. The MAX619 is available in 8-pin DIP and SO packages. Applications Two Battery Cells to 5V Conversion Local 3V-to-5V Conversion Portable Instruments & Handy-Terminals Battery-Powered Microprocessor-Based Systems 5V Flash Memory Programmer Minimum Component DC-DC Converters Remote Data-Acquisition Systems Compact 5V Op-Amp Supply Regulated 5V Supply from Lithium Backup Battery Switching Drive Voltage for MOSFETs in Low-Voltage Systems Pin Configuration MAXKIM Regulated 5V Charge-Pump DC-DC Converter Features Regulated 5V +4% Charge Pump Output Current Guaranteed over Temperature 20mA (VIN > 2V) 50mA (VIN > 3V) # 2V to 3.6V Input Range @ No Inductors; Very Low EMI Noise @ Ultra-Small Application Circuit (0.1in2) # Uses Small, Inexpensive Capacitors @ 500kHz Internal Oscillator @ Logic-Controlled 1A Max Shutdown Supply Current # Shutdown Disconnects Load from Input @ 8-Pin DIP and SO Packages Ordering Information PART TEMP. RANGE PIN-PACKAGE MAX619CPA 0 to +70 8 Plastic DIP MAX619CSA O to +70 850 MAX619C/D 0% to +70C Dice* MAX619EPA -40C to +85C 8 Plastic DIP MAX619ESA -40C to +85C 850 MAX619MJA -55C to +125C 8 CERDIP * Dice are specilied at TA= +25 TC. Typical Operating Circuit TOP VIEW INPUT IN OUT LUTPUT 2Vito 3 BV + rf. st 20mA THF 1OmF . ad T MAAXLAA T e+ EY fe] cr _ MAXB19 = In [2] AAAXLM 7] son ON/OFF] SHDN our [a] AXIS re] AD in Ct C24 c+ [a] is] & 0 ae LL Our DIP!SO Cr | a MA AXLA Maxim integrated Products 1 For free samples & the iatest literature: http:/;www.maxim-ic.com, or phone 1-800-998-8800 6LOXVINNMAX619 Regulated 5V Charge-Pump DC-DC Converter ABSOLUTE MAXIMUM RATINGS VIN to GND oo. re OV to 45.5 Operating Temperature Ranges Vout to GND ow. tettee O.3V to +5.5V MAX619C__ beets SHDN to GND......0...... -0.3V to (VIN + 0.34) MAX619E___.. -40%S to +85C lout Continuous (Note 1).. tne T2OMA MAX619MJA..... te -55C to +125C Continuous Power Dissipation (TA = +70C) Storage Temperature Range -65C to +165C Plastic DIP (derate 9.09mW/% above +70%C) .... cecteeeeee eee BOOS SO (derate 5.88mW/%C above +70C) CERDIP (derate 8.00mW/C above +70C)}...... Lead Temperature (soldering, 10sec}... Note 1: The MAX619 is not short-circuit protected. 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 ihe specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VIN = 2V to 3.6V, C1 = C2 = 0.22uF, C3 = C4 = 10uF, Ta = TMIN to Tmax, unless otherwise noted. Typical values are at Ta = +25C.)} PARAMETER SYMBOL CONDITIONS MIN TYP MAX | UNITS Input Voltage VIN 2 3.6 Vv 2.0V < Vin = 3.6V, OMA < louTs 20mA 3.0V < Vin <3.6, OMA < louT= 50mA, MAX619C Cutput Voltage VouT 48 5.0 5.2 Vv 3.0V < VIN = 3.6V, OmA < louTs 45mA, MAX619E 3.0V < Vin <3.6V, OmA < louTs 40mA, MAX619M Cutput Ripple VRIPPLE No load to full load 100 my No-Load Supply Current lIN 2V < VIN <3.6V, louT= OmA 75 170 WA Shutdown Supply 2V < Vin <3.6V, lout = 0mA, | MAX619C/E 0.02 1 uA Current VSHDN = VIN MAX619M 10 VIN = 3V, louT = 20mA 82 Etficiency Eft VIN = 3V, louT = 30mA 82 % Vin = 2, lout = 20mA 80 Switching Frequency At full load 500 kHz VIH 07x VIN SHDN Input Threshold Vv VIL o4 SHDN Input it I Vv. Vv MAX6 19G/E #1 HA nput Curren = P IW SHDN = SIN MAX619M +10 2 PAAKLAARegulated 5V Charge-Pump DC-DC Converter Typical Operating Characteristics (TA = +25, unless otherwise noted.) EFFICIENCY vs. OUTPUT CURRENT NO-LOAD INPLT CURRENT AND INPUT VOLTAGE INPUT CURRENT vs. OUTPUT CURRENT ys, INPUT VOLTAGE go 200 1000 DB as n=1 180 SHDN =0V 160 100 2 80 140 5 = 120 =z 10 oO -t = 75 = = i = 100 Vin = m7 ~ a0 18 10 nh 70 20 u BO 24 27 8 se 01 SHDN = Vin 20 34 50 0 oot 1 10 100 0 10 20 30 40 50 60 70 80 90 100 15 20 25 30 SB 400 45 lout (mA} lout (mA) Vin () QUTPUT VOLTAGE vs. QUTPUT CURRENT OUTPUT VOLTAGE vs. INPUT VOLTAGE EFFICIENCY vs. INPUT VOLTAGE 90 =3V Iqur=10mA 85 2 20 = & E fi 75 = e L ui 70 85 80 15 20 25 30 435 40 45 50 55 80 15 20 25 30 35 406 lout (mA) Vin (Y) Vin () LOAD-TRANSIENT RESPONSE UNE-TRANSIENT RESPONSE (lout = 20mA) sopreee deans ae ye mo eS : i : = : . a. : De et 1b tetanatieninnnndl Bo. : seen : 2 : : : i f : 2msidiv 2msidiv TOP TRACE GUTPUT CURRENT, OmA to 25mA, 10mAdi Roan = 250.8, Vout =5, lout = 20mA BOTTOM TRACE CUTPUT VOLTAGE 5mVidiv, AC-COUPLED TOP TRACE Viy=2 to OV, 1Walv BOTTOM TRACE OUTPUT VOLTAGE, 50mW div, AC-COUPLED MAAXKLM 3 6LOXVINNMAX619 Regulated 5V Charge-Pump DC-DC Converter Pin Description PIN | NAME FUNCTION 1 Gi+ = | Positive Terminal for C1 2 IN Input Supply Voltage 3 our | x54 Out Ytase. Your = OV when in 4 C2+ | Positive Terminal for C2 5 C2- | Negative Terminal for C2 6 GND | Ground 7 | SHDN | Active-High CMOS Logic-Level Shutdown Input 8 C1- | Negative Terminal for C1 Detailed Description Operating Principle The MAX613 provides a regulated 5V output from a 2V to 3.6V (two battery cells) input. Internal charge pumps and external capacitors generate the 5V output, elimi- nating the need for inductors. The output voltage is regulated to 5V +4% by a pulse-skipping controller that turns on the charge pump when the output voltage begins to dreop. To maintain the greatest efficiency over the entire input voltage range, the MAX619s internal charge pump operates as a voltage doubler when Vin ranges from 3.0V to 3.6V, and as a voltage trpler when VIN ranges from 2.0V to 2.5V. When VIN ranges from 2.5V to 3.0V, the MAX619 switches between doubler and tripler mode on alternating cycles, making a 2.5 x VIN charge pump. To further enhance efficiency over the input range, an internal comparator selects the higher of VIN or VouT to run the MAX619's internal circuitry. Efficiency with VIN = 2V and louT = 20mA is typically 80%. Figure 1 shows a detailed block diagram of the MAX613. In tripler mode, when the S31 switches close, the 32 switches open and capacitors C1 and C2 charge up to Vin. On the second half of the cycle, C1 and G2 are connected in series between IN and OUT when the $1 switches open and the S2 switches close, as shown in Figure 1. In doubler mode, only C2 is used. During one oscillator cycle, energy is transferred from the input to the charge-pump capacitors, and then from the charge-pump capacitors to the output capaci- tor and load. The number of cycles within a given time frame increases as the load increases or as the input supply voltage decreases. In the limiting case, the charge pumps operate continuously, and the oscillator frequency is nominally 500kHz. Shuidown Mode The MAX619 enters low-power shutdown mode when SHDN is a logic high. SHDN is a CMOS-compatible input. In shutdown mode, the charge-pump switching action is halted, OUT is disconnected from IN, and VOUT falls to OV. Connect SHDN te ground fer normal operation. When Vin = 3.6V, Vout typically reaches 5V in 0.5ms under no-load conditions after SHDN goes low. PAAKLAARegulated 5V Charge-Pump DC-DC Converter VinVour CONTROL * SWITCHES SHOWN IN TRIPLER MODE DISCHARGE CYCLE Figure 1. Block Diagram MAAXLM 5 6LOXVINNMAX619 Regulated 5V Charge-Pump DC-DC Converter Applications Information Capacitor Selection Gharge-Pump Capacitors Ci and C2 The values of charge-pump capacitors C1 and C2 are critical to ensure adequate output current and avoid excessive peak currents. Use values in the range of 0.22uF to 1.0uF. Larger capacitors (up to 50u,F) can be used, but larger capacitors will increase output rip- ple. Ceramic or tantalum capacitors are recommend- ed. input and Output Capacitors, C3 and C4 The type of input bypass capacitor (C3) and output fil- ter capacitor (C4) used is not critical, but it does affect performance. Tantalums, ceramics, or aluminum elec- trolytics are suggested. For smallest size, use Sprague 595D106X0010A2 surface-mount capacitors, which measure 3.7mm x 1.8mm (0.148in x 0.072in). For low- est ripple, use large, low effective-series-resistance (ESR) ceramic or tantalum capacitors. For lowest cost, use aluminum electrolytic or tantalum capacitors. Figure 2 shows the component values for proper oper- ation using minimal board space. The input bypass capacitor (C3) and output filter capacitor (C4) should both be at least 10uF when using aluminum electrolyt- ics or Spragues miniature 595D series of tantalum chip capacitors. Table 1. Capacitor Suppliers When using ceramic capacitors, the values of C3 and C4 can be reduced to 2uF and 1pF, respectively. If the input supply source impedance is very low, C3 may not be necessary. Many capacitors exhibit 40% to 50% variation over temperature. Compensate for capacitor temperature coefficient by selecting a larger nominal value to ensure proper operation over temperature. Table 1 lists capacitor suppliers. 1 4 Ci+ C2+ MAAXIAA PL Ct MAXEIg 020uF BF oy cz sy IN SHDN ee" SY cnn ate BY 4% @ 20imA + Figure 2. Two-CGell ta 5V Application Cirouit SUPPLIER PHONE NUMBER FAX NUMBER CAPACITOR CAPACITOR TYPE* GRM42-6Z5U1 0M50 0.1uF ceramic (SM) . GRM42-625U22M50 0.22uF ceramic (SM) Murata Erie (814) 237-1431 (814) 238-0490 : RPI23Z5U105M50V 1.0u.F ceramic (TH) RPE121Z5U1 04M50V 0.14.F ceramic (TH) Sprague Electric (603) 224-1961 (603) 224-1430 (smallest size) (207) 327-4140 (207) 324-7223 595D106X0010A2 1OuF tantalum (SM) * Note: (SM) denotes surface-mount component, (TH) denotes through-hole component. PAAKLAARegulated 5V Charge-Pump Layout Considerations The MAX619's high oscillator frequency makes good layout important. A good layout ensures stability and helps maintain the output veltage under heavy loads. For best performance, use very short connections to the capacitors. Parafleling Devices Two MAX619s can be placed in parallel to increase output drive capability. The IN, OUT, and GND pins can be paralleled, but Ci and C2 pins cannot. The input bypass capacitor and output filter capacitor are, to some extent, shared when two circuits are paral- leled. If the circuits are physically close together, it may be possible to use a single bypass and a single output capacitor, each with twice the value of the single circuit. If the MAX619s cannot be placed close togeth- er, use separate bypass and output capacitors. The amount of output ripple observed will determine whether single input bypass and output filter capacitors can be used. maxim | 7 TL _] MAX619 | oy. IN OUT GND INPUT i | BN, 40mA + + T Ll maum| T _ T_] MAX619 | - IN OUT GND IKK Figure 3. Paralleling Two MAX61 9s MAAXLM DC-DC Converter Chip Topography 0.115 (2.921mm) OUT (1.828mm) TRANSISTOR COUNT: 599; SUBSTRATE CONNECTED TO GND. 6LOXVINN