Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - DC/DC voltage regulator Switched-capacitor voltage converter uMAX 8

19-0239; Rev 3; 8/13

MAX860/MAX861

50mA, Frequency-Selectable,

Switched-Capacitor Voltage Converters

For pricing, delivery, and ordering information, please contact Maxim Direct

at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.

_______________General Description

The MAX860/MAX861 charge-pump voltage converters

invert input voltages ranging from +1.5V to +5.5V, or

double input voltages ranging from +2.5V to +5.5V.

Because of their high switching frequencies, these

devices use only two small, low-cost capacitors. Their

50mA output makes switching regulators unnecessary,

eliminating inductors and their associated cost, size,

and EMI. Greater than 90% efficiency over most of the

load-current range, combined with a typical operating

current of only 200µA (MAX860), provides ideal perfor-

mance for both battery-powered and board-level volt-

age-conversion applications.

A frequency-control (FC) pin provides three switching-

frequencies to optimize capacitor size and quiescent

current and to prevent interference with sensitive cir-

cuitry. Each device has a unique set of three available

frequencies. A shutdown (S

—

–

) pin reduces current

consumption to less than 1µA. The MAX860/MAX861

are suitable for use in applications where the ICL7660

and MAX660's switching frequencies are too low. The

MAX860/MAX861 are available in 8-pin µMAX

and

SO packages.

________________________Applications

Portable Computers

Medical Instruments

Interface Power Supplies

Hand-Held Instruments

Operational-Amplifier Power Supplies

____________________________Features

o 8-Pin, 1.11mm High µMAX Package

o Invert or Double the Input Supply Voltage

o Three Selectable Switching Frequencies

o High Frequency Reduces Capacitor Size

o 87% Efficiency at 50mA

o 200µA Quiescent Current (MAX860)

o 1µA Shutdown Supply Current

o 600mV Voltage Drop at 50mA Load

o 12Ω Output Resistance

______________Ordering Information

SHDN

OUT

C1-

GND

C1+

MAX860

MAX861

SO/μMAX

TOP VIEW

__________________Pin Configuration

C1+

GND

C1- OUT

SHDN

MAX860

MAX861

C1+

GND

C1- OUT

SHDN

MAX860

MAX861

INPUT

VOLTAGE

+1.5V TO +5.5V

INVERTED

NEGATIVE

OUTPUT

INPUT

VOLTAGE

+2.5V TO +5.5V

DOUBLED

POSITIVE

OUTPUT

10μF

VOLTAGE INVERTER

POSITIVE VOLTAGE DOUBLER

PART TEMP RANGE PIN-PACKAGE

MAX860ISA -25°C to +85°C 8 SO

MAX860IUA -25°C to +85°C 8 µMAX

MAX860C/D 0°C to +70°C Dice*

MAX860ESA -40°C to +85°C 8 SO

MAX860MJA -55°C to +125°C 8 CERDIP†

MAX860MSA/PR3

-55°C to +125°C 8 SO

MAX861ISA -25°C to +85°C 8 SO

MAX861IUA -25°C to +85°C 8 µMAX

MAX861C/D 0°C to +70°C Dice*

MAX861ESA -40°C to +85°C 8 SO

MAX861MJA -55°C to +125°C 8 CERDIP†

__________Typical Operating Circuit

Dice are tested at T

= +25°C, DC parameters only.

†

Contact factory for availability.

µMAX is a registered trademark of Maxim Integrated Products, Inc.

Summary of content (11 pages)

PAGE 1
MAX860/MAX861 50mA, Frequency-Selectable, Switched-Capacitor Voltage Converters _______________General Description The MAX860/MAX861 charge-pump voltage converters invert input voltages ranging from +1.5V to +5.5V, or double input voltages ranging from +2.5V to +5.5V. Because of their high switching frequencies, these devices use only two small, low-cost capacitors. Their 50mA output makes switching regulators unnecessary, eliminating inductors and their associated cost, size, and EMI.
PAGE 2
MAX860/MAX861 50mA, Frequency-Selectable, Switched-Capacitor Voltage Converters ABSOLUTE MAXIMUM RATINGS Supply Voltage (VDD to GND or GND to OUT) ...................+6.0V –———– Input Voltage Range (LV, FC, S H D N ) ...................(OUT - 0.3V) to (VDD + 0.3V) Continuous Output Current (OUT, VDD) .............................60mA Output Short-Circuit to GND (Note 1).......................................1s Continuous Power Dissipation (TA = +70°C) SO (derate 5.88mW/°C above +70°C) ......................
PAGE 3
MAX860/MAX861 50mA, Frequency-Selectable, Switched-Capacitor Voltage Converters ELECTRICAL CHARACTERISTICS (continued) –———– (Typical Operating Circuit (Inverter), VDD = +5V, SHDN = VDD, FC = LV = GND, C1 = C2 = 10µF (Note 2), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 4
MAX860/MAX861 50mA, Frequency-Selectable, Switched-Capacitor Voltage Converters __________________________________________Typical Operating Characteristics (All curves generated using the inverter circuit shown in the Typical Operating Circuits with LV = GND and TA = +25°C, unless otherwise noted. Test results also valid for doubler mode with LV = OUT and TA = +25°C. All capacitor values used are those recommended in Table 3, unless otherwise noted.
PAGE 5
MAX860/MAX861 50mA, Frequency-Selectable, Switched-Capacitor Voltage Converters ____________________________Typical Operating Characteristics (continued) (All curves generated using the inverter circuit shown in the Typical Operating Circuits with LV = GND and TA = +25°C, unless otherwise noted. Test results also valid for doubler mode with LV = OUT and TA = +25°C. All capacitor values used are those recommended in Table 3, unless otherwise noted.
PAGE 6
MAX860/MAX861 50mA, Frequency-Selectable, Switched-Capacitor Voltage Converters _______________Detailed Description The MAX860/MAX861 capacitive charge pumps either invert or double the voltage applied to their inputs. For highest performance, use low equivalent series resistance (ESR) capacitors. See the Capacitor Selection section for more details. The frequency-control (FC) pin allows you to choose one of three switching frequencies; these three selectable frequencies are different for each device.
PAGE 7
MAX860/MAX861 50mA, Frequency-Selectable, Switched-Capacitor Voltage Converters Table 2. Switching-Frequency Trade-Offs LOWER FREQUENCY Larger HIGHER FREQUENCY Smaller C1, C2 Values Larger Smaller Supply Current Smaller Larger ATTRIBUTE Output Ripple __________Applications Information Capacitor Selection The MAX860/MAX861 are tested using 10µF capacitors for both C1 and C2, although smaller or larger values can be used (Table 3).
PAGE 8
MAX860/MAX861 50mA, Frequency-Selectable, Switched-Capacitor Voltage Converters Flying Capacitor, C1 Increasing the size of the flying capacitor reduces the output resistance. Output Capacitor, C2 Increasing the size of the output capacitor reduces the output ripple voltage. Decreasing its ESR reduces both output resistance and ripple.
PAGE 9
MAX860/MAX861 50mA, Frequency-Selectable, Switched-Capacitor Voltage Converters Table 5. Product Selection Guide +VIN 8 2 C1 3 MAX860 MAX861 4 7 PART NUMBER OUTPUT CURRENT (mA) MAX660 100 6.5 5/40 MAX665 100 6.5 5/40 MAX860 50 12 6/50/130 MAX861 50 12 13/100/250 ICL7660 10 55 5 D1, D2 = 1N4148 D1 5 OUTPUT SWITCHING RESISTANCE FREQUENCY (Ω) (kHz) VOUT = -VIN C2 D2 C3 C4 VOUT = (2VIN) (VFD1) - (VFD2) Figure 3.
PAGE 10
MAX860/MAX861 50mA, Frequency-Selectable, Switched-Capacitor Voltage Converters Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.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. 10 PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.
PAGE 11
MAX860/MAX861 50mA, Frequency-Selectable, Switched-Capacitor Voltage Converters Revision History PAGES CHANGED REVISION NUMBER REVISION DATE 0 7/94 Initial release 2 4/03 Updated Electrical Characteristics and Cascading Devices section. 3, 8 3 8/13 Added MAX860MSA/PR3 to data sheet and revised Absolute Maximum Ratings. 1, 2 DESCRIPTION — Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product.