MAX1683EUK+T - Hytronics

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

General Description

The ultra-small MAX1682/MAX1683 monolithic, CMOS

charge-pump voltage doublers accept input voltages

ranging from +2.0V to +5.5V. Their high voltage-con-

version efficiency (over 98%) and low operating current

(110µA for MAX1682) make these devices ideal for

both battery-powered and board-level voltage-doubler

applications.

Oscillator control circuitry and four power MOSFET

switches are included on-chip. The MAX1682 operates

at 12kHz, and the MAX1683 operates at 35kHz. A typi-

cal application includes generating a 6V supply to

power an LCD display in a hand-held PDA. Both parts

are available in a 5-pin SOT23 package and can deliver

30mA with a typical voltage drop of 600mV.

________________________Applications

Small LCD Panels

Cell Phones

Handy-Terminals

PDAs

____________________________Features

♦5-Pin SOT23 Package

♦+2.0V to +5.5V Input Voltage Range

♦98% Voltage-Conversion Efficiency

♦110µA Quiescent Current (MAX1682)

♦Requires Only Two Capacitors

♦Up to 45mA Output Current

MAX1682/MAX1683

Switched-Capacitor Voltage Doublers

________________________________________________________________

Maxim Integrated Products

OUT

INC1-

15C1+GND

MAX1682

MAX1683

SOT23-5

TOP VIEW

Pin Configuration

VOLTAGE DOUBLER

C1+

C1-

OUT

GND

INPUT

SUPPLY

VOLTAGE

OUTPUT

VOLTAGE

2 x VIN

MAX1682

MAX1683

VIN

Typical Operating Circuit

19-1305; Rev 3; 11/10

PART

MAX1682EUK+T -40°C to +85°C

TEMP

RANGE

PIN-

PACKAGE

5 SOT23-5

Ordering Information

Note: These parts are available in tape-and-reel only. Minimum

order quantity is 2500 pieces.

Denotes a lead(Pb)-free/RoHS-compliant package.

T = Tape and reel.

MAX1683EUK+T -40°C to +85°C 5 SOT23-5

SOT

TOP MARK

ACCL

ACCM

MAX1682/MAX1683

Switched-Capacitor Voltage Doublers

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VIN = +5.0V, capacitor values from Table 2, TA= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)

ELECTRICAL CHARACTERISTICS

(VIN = +5.0V, capacitor values from Table 2, TA= -40°C to +85°C, unless otherwise noted.) (Note 3)

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.

Note 2: Once started, the MAX1682/MAX1683 typically operate down to 1V.

Note 3: Specifications at -40°C to +85°C are guaranteed by design.

IN to GND .................................................................+6V to -0.3V

OUT to GND.......................................................+12V, VIN - 0.3V

OUT Output Current............................................................50mA

Output Short-Circuit Duration .................................1sec (Note 1)

Continuous Power Dissipation (TA= +70°C)

SOT23-5 (derate 7.1mW/°C above +70°C)...................571mW

Operating Temperature Range

MAX1682EUK/MAX1683EUK ...........................-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +160°C

Lead Temperature (soldering, 10sec) .............................+300°C

Soldering Temperature (reflow) .......................................+260°C

(Note 2)

TA= +25°C

IOUT = 0mA, TA= +25°C

CONDITIONS

V1Minimum Operating Voltage

µA

230 310

110 145

No-Load Supply Current

8.4 12 15.6 kHz

24.5 35 45.5

Oscillator Frequency

%98 99.9Voltage Conversion Efficiency

UNITSMIN TYP MAXPARAMETER

Note 1: Avoid shorting OUT to GND, as it may damage the device. For temperatures above +85°C, shorting OUT to GND even

instantaneously will damage the device.

MAX1682

MAX1683

RLOAD = 10kΩTA= +25°C

TA= 0°C to +85°C V

2.1 1.8 5.5

2.0 1.7 5.5

Supply Voltage Range

MAX1682

MAX1683

TA= +25°C

TA= 0°C to +85°C

IOUT = 5mA 20 50 Ω

Output Resistance

IOUT = 0mA

IOUT = 5mA

MAX1683

MAX1682

RLOAD = 10kΩ

MAX1683

MAX1682

CONDITIONS

%97Voltage Conversion Efficiency

Ω65Output Resistance

kHz

17.5 57.8

Oscillator Frequency 6.6 18.6

V2.3 5.5Supply Voltage Range

µA

350

160

No-Load Supply Current

UNITSMIN TYP MAXPARAMETER

MAX1682/MAX1683

Switched-Capacitor Voltage Doublers

_______________________________________________________________________________________ 3

1.0 2.5 3.01.5 2.0 3.5 4.0 4.5 5.0 5.5

OUTPUT RESISTANCE

vs. SUPPLY VOLTAGE

MAX1682/83 TOC1

VIN (V)

OUTPUT RESISTANCE (Ω)

MAX1683, C1 = C2 = 3.3μF

MAX1683, C1 = C2 = 10μF

MAX1682, C1 = C2 = 10μF

-40 0-20 20 40 60 80

MAX1682 OUTPUT RESISTANCE

vs. TEMPERATURE

MAX1682/83 TOC02

TEMPERATURE (°C)

OUTPUT RESISTANCE (Ω)

ILOAD = 5mA

VIN = 5V

VIN = 3.3V

VIN = 2V

-40 0-20 20406080

MAX1683 OUTPUT RESISTANCE

vs. TEMPERATURE

MAX1682/83 TOC03

TEMPERATURE (°C)

OUTPUT RESISTANCE (Ω)

ILOAD = 5mA

VIN = 5V

VIN = 3.3V

VIN = 2V

100

120

015205 10 253035

MAX1682 OUTPUT RESISTANCE

vs. CAPACITANCE

MAX1682/83 TOC4

CAPACITANCE (μF)

OUTPUT RESISTANCE (Ω)

VIN = 5V VIN = 3.3V

VIN = 2V

200

100

400

300

600

500

700

900

800

1000

010155 2025303540

MAX1683

OUTPUT VOLTAGE RIPPLE

vs. OUTPUT CURRENT

MAX1682/83 TOC07

IOUT (mA)

VRIPPLE (mV)

C1 = C2 =1μF

C1 = C2 = 3.3μF

C1 = C2 = 10μF

0 5 10 15 20 25 30 35

MAX1683 OUTPUT RESISTANCE

vs. CAPITANCE

MAX1682/83 TOC05

CAPACITANCE (μF)

OUTPUT RESISTANCE (Ω)

VIN = 2V

VIN = 3.3V

VIN = 5V

200

100

400

300

500

600

700

800

010155 2025303540

MAX1682

OUTPUT VOLTAGE RIPPLE

vs. OUTPUT CURRENT

MAX1682/83 TOC06

IOUT (mA)

VRIPPLE (mV)

C1 = C2 = 3.3μF

C1 = C2 = 10μF

C1 = C2 = 33μF

100

150

200

250

300

1.0 2.01.5 2.5 3.0 3.5 4.0 4.5 5.0 5.5

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX1682/83 TOC09

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (μA)

MAX1683

MAX1682

Typical Operating Characteristics

(Typical Operating Circuit, VIN = +5V, C1 = C2 = 10µF for the MAX1682 and 3.3µF for the MAX1683, TA= +25°C, unless otherwise

noted.)

MAX1682/MAX1683

Switched-Capacitor Voltage Doublers

4 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(Typical Operating Circuit, VIN = +5V, C1 = C2 = 10µF for the MAX1682 and 3.3µF for the MAX1683, TA= +25°C, unless otherwise

noted.)

11.0

11.5

12.0

12.5

-40 0 20-20 406080

MAX1682 OSCILLATOR FREQUENCY

vs. TEMPERATURE

MAX1682/83 TOC10

TEMPERATURE (°C)

OSCILLATOR FREQUENCY (kHz)

VIN = 5V

VIN = 3.3V

VIN = 2V

-40 0 20-20 406080

MAX1683 OSCILLATOR FREQUENCY

vs. TEMPERATURE

MAX1682/83 TOC11

TEMPERATURE (°C)

OSCILLATOR FREQUENCY (kHz)

VIN = 5V

VIN = 3.3V

VIN = 2V

0 1015205 253035 4540 50

MAX1682 OUTPUT VOLTAGE

vs. OUTPUT CURRENT

MAX1682/83 TOC12

OUTPUT CURRENT (mA)

OUTPUT VOLTAGE (V)

VIN = 5V

VIN = 3.3V

VIN = 2V

0 1015205 253035 4540 50

MAX1683 OUTPUT VOLTAGE

vs. OUTPUT CURRENT

MAX1682/83 TOC13

OUTPUT CURRENT (mA)

OUTPUT VOLTAGE (V)

VIN = 5V

VIN = 3.3V

VIN = 2V

20μs/div

VOUT

20mV/div

ILOAD = 5mA, VIN = 5V, C1 = C2 = 10μF

MAX1682

OUTPUT RIPPLE

MAX1682toc16

100

0105 15202530

MAX1682 EFFICIENCY vs.

LOAD CURRENT

MAX1682/83 TOC14

LOAD CURRENT (mA)

EFFICIENCY (%)

VIN = 5V

VIN = 3.3V

VIN = 2V

100

0105 15202530

MAX1683 EFFICIENCY vs.

LOAD CURRENT

MAX1682/83 TOC15

LOAD CURRENT (mA)

EFFICIENCY (%)

VIN = 5V

VIN = 3.3V

VIN = 2V

MAX1683

OUTPUT RIPPLE

MAX1682toc17

ILOAD = 5mA, VIN = 5V, C1 = 3.3μF, C2 = 10μF

20μs/div

VOUT

20mV/div

0.5

1.0

1.5

2.0

2.5

700 30 10100 70300 7 3 1 0.7 0.3

START-UP VOLTAGE

vs. RESISTIVE LOAD

MAX1682toc18

RLOAD (kΩ)

VSTART (V)

MAX1682

MAX1683

_______________Detailed Description

The MAX1682/MAX1683 capacitive charge pumps

double the voltage applied to their input. Figure 1

shows a simplified functional diagram of an ideal volt-

age doubler. During the first half-cycle, switches S1

and S2 close, and capacitor C1 charges to VIN. During

the second half cycle, S1 and S2 open, S3 and S4

close, and C1 is level shifted upward by VIN volts. This

connects C1 to the reservoir capacitor C2, allowing

energy to be delivered to the output as necessary. The

actual voltage is slightly lower than 2 x VIN, since

switches S1–S4 have resistance and the load drains

charge from C2.

Charge-Pump Output

The MAX1682/MAX1683 have a finite output resistance

of about 20Ω(Table 2). As the load current increases,

the devices’ output voltage (VOUT) droops. The droop

equals the current drawn from VOUT times the circuit’s

output impedance (RS), as follows:

VDROOP = IOUT x RS

VOUT = 2 x VIN - VDROOP

Efficiency Considerations

The power efficiency of a switched-capacitor voltage

converter is affected by three factors: the internal losses

in the converter IC, the resistive losses of the capacitors,

and the conversion losses during charge transfer

between the capacitors. The total power loss is:

The internal losses are associated with the IC’s internal

functions, such as driving the switches, oscillator, etc.

These losses are affected by operating conditions such

as input voltage, temperature, and frequency.

The next two losses are associated with the voltage

converter circuit’s output resistance. Switch losses

occur because of the on-resistance of the MOSFET

switches in the IC. Charge-pump capacitor losses

occur because of their ESR. The relationship between

these losses and the output resistance is as follows:

where fOSC is the oscillator frequency. The first term is

the effective resistance from an ideal switched-

capacitor circuit (Figures 2a and 2b).

IxR

RfxC

R ESR

ESR

PUMP CAPACITOR LOSSES SWITCH LOSSES

OUT OUT

OUT

OSC

SWITCHES C

≅

()

124

ΣPP

LOSS INTERNAL LOSSES

PUMP CAPACITOR LOSSES

CONVERSION LOSSES

MAX1682/MAX1683

Switched-Capacitor Voltage Doublers

_______________________________________________________________________________________ 5

_____________________Pin Description

NAME FUNCTION

1GND Ground

2OUT Doubled Output Voltage. Connect C2

between OUT and GND.

3C1- Negative Terminal of the Flying

Capacitor

4IN Input Supply

5C1+ Positive Terminal of the Flying

Capacitor

Figure 2a. Switched-Capacitor Model

V+

C2 RL

VOUT

Figure 1. Simplified Functional Diagram of Ideal Voltage

Doubler

VIN

VOUT

Figure 2b. Equivalent Circuit

REQUIV =

REQUIV

VOUT

V+

f × C1 C2

MAX1682/MAX1683

Conversion losses occur during the charge transfer

between C1 and C2 when there is a voltage difference

between them. The power loss is:

where VRIPPLE is the peak-to-peak output voltage ripple

determined by the output capacitor and load current

(see Output Capacitor section). Choose capacitor val-

ues that decrease the output resistance (see Flying

Capacitor section).

Applications Information

Flying Capacitor (C1)

To maintain the lowest output resistance, use capaci-

tors with low ESR. Suitable capacitor manufacturers are

listed in Table 1. The charge-pump output resistance is

a function of C1 and C2’s ESR and the internal switch

resistance, as shown in the equation for ROUT in the

Efficiency Considerations section.

Minimizing the charge-pump capacitor’s ESR mini-

mizes the total resistance. Suggested values are listed

in Tables 2 and 3.

Using a larger flying capacitor reduces the output

impedance and improves efficiency (see the Efficiency

Considerations section). Above a certain point, increas-

ing C1’s capacitance has a negligible effect because

the output resistance becomes dominated by the inter-

nal switch resistance and capacitor ESR (see the

Output Resistance vs. Capacitance graph in the

Typical Operating Characteristics). Table 2 lists the

most desirable capacitor values—those that produce a

low output resistance. But when space is a constraint, it

may be necessary to sacrifice low output resistance for

the sake of small capacitor size. Table 3 demonstrates

how the capacitor affects output resistance.

Output Capacitor (C2)

Increasing the output capacitance reduces the output

ripple voltage. Decreasing its ESR reduces both output

resistance and ripple. Smaller capacitance values can

be used with light loads. Use the following equation to

calculate the peak-to-peak ripple:

VRIPPLE = IOUT / (fOSC x C2) + 2 x IOUT x ESRC2

Input Bypass Capacitor

Bypass the incoming supply to reduce its AC imped-

ance and the impact of the MAX1682/MAX1683’s

switching noise. When loaded, the circuit draws a con-

tinuous current of 2 x IOUT. A 0.1µF bypass capacitor is

sufficient.

P / C1 4V V

/ C2 2V V V x f

CONVERSION LOSS 12IN

OUT

1 2 OUT RIPPLE 2RIPPLE OSC

=−

⎛

⎝

⎜⎞

⎠

⎟+

⎡

⎣

⎢

−

⎛

⎝

⎜⎞

⎠

⎟⎤

⎦

⎥

Switched-Capacitor Voltage Doublers

6 _______________________________________________________________________________________

Table 1. Recommended Capacitor Manufacturers

Table 2. Suggested Capacitor Values for

Low Output Resistance

Table 3. Suggested Capacitor Values for

Minimum Size

MANUFACTURER

AVX

PRODUCTION METHOD SERIES

TPS

PHONE FAX

803-946-0690 803-448-2170

Matsuo 267 714-969-2491 714-960-6492Surface-Mount Tantalum

Sprague 593D, 595D 603-224-1961 603-224-1430

AVX X7R 803-946-0590 803-626-3123

Surface-Mount Ceramic Matsuo X7R 714-969-2491 714-960-6492

PART FREQUENCY

(kHz)

MAX1682 12

MAX1683 35

CAPACITOR

VALUE (µF)

3.3

TYPICAL

ROUT (Ω)

PART FREQUENCY

(kHz)

CAPACITOR

VALUE (µF)

MAX1682 12 3.3

TYPICAL

ROUT (Ω)

35MAX1683 35

Cascading Devices

Devices can be cascaded to produce an even larger

voltage (Figure 3). The unloaded output voltage is nom-

inally (n + 1) x VIN, where n is the number of voltage

doublers used. This voltage is reduced by the output

resistance of the first device multiplied by the quiescent

current of the second. The output resistance increases

when devices are cascaded. Using a two-stage dou-

bler as an example, output resistance can be approxi-

mated as ROUT = 2 x ROUT1 + ROUT2, where ROUT1 is

the output resistance of the first stage and ROUT2 is the

output resistance of the second stage. A typical value

for a two-stage voltage doubler is 60Ω(with C1 at 10µF

for MAX1682 and 3.3µF for MAX1683). For n stages

with the same C1 value, ROUT = (2n- 1) x ROUT1.

Paralleling Devices

Paralleling multiple MAX1682 or MAX1683s reduces

the output resistance. Each device requires its own

pump capacitor (C1), but the reservoir capacitor (C2)

serves all devices (Figure 4). Increase C2’s value by a

factor of n, where n is the number of parallel devices.

Figure 4 shows the equation for calculating output

resistance.

Layout and Grounding

Good layout is important, primarily for good noise per-

formance. To ensure good layout, mount all compo-

nents as close together as possible, keep traces short

to minimize parasitic inductance and capacitance, and

use a ground plane.

MAX1682/MAX1683

Switched-Capacitor Voltage Doublers

_______________________________________________________________________________________ 7

MAX1682

MAX1683

C1+ IN

OUT

GND

C1-

MAX1682

MAX1683

C1+

INPUT

SUPPLY

VOLTAGE

OUTPUT

VOLTAGE

OUT

GND

C1-

Figure 3. Cascading Devices

MAX1682

MAX1683

ROUT = ROUT OF SINGLE DEVICE

NUMBER OF DEVICES C2

C1+ IN

OUT

GND

C1-

MAX1682

MAX1683

C1+

INPUT

SUPPLY

VOLTAGE

OUTPUT

VOLTAGE

OUT

GND

C1-

Figure 4. Paralleling Devices

MAX1682/MAX1683

Switched-Capacitor Voltage Doublers

8 _______________________________________________________________________________________

SOT-23 5L .EPS

Package Information

For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the

package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the

package regardless of RoHS status.

PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.

5 SOT23 U5+2 21-0057 90-0174

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.

9_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

Switched-Capacitor Voltage Doublers

Revision History

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

3 11/10 Added lead-free parts 1