MAX1044CSA ,Switched-Capacitor Voltage ConvertersApplications include generating a -5V supply from aPART TEMP. RANGE PIN-PACKAGE+5V logic supply to ..
MAX1044CSA ,Switched-Capacitor Voltage ConvertersGeneral Description ________
MAX1044CSA+ ,Switched-Capacitor Voltage ConvertersMAX1044/ICL766019-4667; Rev 1; 7/94Switched-Capacitor Voltage Converters_______________
MAX1044CSA+T ,Switched-Capacitor Voltage ConvertersFeaturesThe MAX1044 and ICL7660 are monolithic, CMOS' Miniature µMAX Packageswitched-capacitor volt ..
MAX1044EPA ,Switched-Capacitor Voltage ConvertersFeaturesThe MAX1044 and ICL7660 are monolithic, CMOS' Miniature µMAX Packageswitched-capacitor volt ..
MAX1044ESA ,Switched-Capacitor Voltage ConvertersMAX1044/ICL766019-4667; Rev 1; 7/94Switched-Capacitor Voltage Converters_______________
MAX3387EEUG+T ,3V, ±15kV ESD-Protected, AutoShutdown Plus RS-232 Transceiver for PDAs and Cell PhonesFeaturesThe MAX3387E 3V powered TIA/EIA-232 and V.28/V.24♦ V Pin for Compatibility with Mixed-Volta ..
MAX3387EEUG+T ,3V, ±15kV ESD-Protected, AutoShutdown Plus RS-232 Transceiver for PDAs and Cell PhonesMAX3387E19-1561; Rev 3; 6/103V, ±15kV ESD-Protected, AutoShutdown PlusRS-232 Transceiver for PDAs a ..
MAX3387EEUG+T ,3V, ±15kV ESD-Protected, AutoShutdown Plus RS-232 Transceiver for PDAs and Cell PhonesFeaturesThe MAX3387E 3V powered TIA/EIA-232 and V.28/V.24♦ V Pin for Compatibility with Mixed-Volta ..
MAX3387EEUG-T ,3V, ±15kV ESD-Protected, AutoShutdown Plus RS-232 Transceiver for PDAs and Cell PhonesELECTRICAL CHARACTERISTICS(V = V = +3.0V to +5.5V; C1–C4 = 0.1µF, tested at +3.3V ±10%; C1 = 0.047µ ..
MAX3388ECUG+ ,2.5V, ±15kV ESD-Protected RS-232 Transceivers for PDAs and Cell PhonesELECTRICAL CHARACTERISTICS(V = V = +2.35V to +3.0V, C1–C4 = 0.1µF, T = T to T , unless otherwise no ..
MAX3388ECUG+T ,2.5V, ±15kV ESD-Protected RS-232 Transceivers for PDAs and Cell PhonesApplicationsto +3.0V supply with a dual charge pump. The chargeSubnotebook/Palmtop Computerspump re ..
MAX1044CPA-MAX1044CSA-MAX1044EPA-MAX1044ESA
Switched-Capacitor Voltage Converters
_______________General DescriptionThe MAX1044 and ICL7660 are monolithic, CMOS
switched-capacitor voltage converters that invert, dou-
ble, divide, or multiply a positive input voltage. They are
pin compatible with the industry-standard ICL7660 and
LTC1044. Operation is guaranteed from 1.5V to 10V with
no external diode over the full temperature range. They
deliver 10mA with a 0.5V output drop. The MAX1044
has a BOOST pin that raises the oscillator frequency
above the audio band and reduces external capacitor
size requirements.
The MAX1044/ICL7660 combine low quiescent current
and high efficiency. Oscillator control circuitry and four
power MOSFET switches are included on-chip.
Applications include generating a -5V supply from a
+5V logic supply to power analog circuitry. For applica-
tions requiring more power, the MAX660 delivers up to
100mA with a voltage drop of less than 0.65V.
________________________Applications-5V Supply from +5V Logic Supply
Personal Communications Equipment
Portable Telephones
Op-Amp Power Supplies
EIA/TIA-232E and EIA/TIA-562 Power Supplies
Data-Acquisition Systems
Hand-Held Instruments
Panel Meters
____________________________FeaturesMiniature µMAX Package1.5V to 10.0V Operating Supply Voltage Range98% Typical Power-Conversion EfficiencyInvert, Double, Divide, or Multiply Input VoltagesBOOST Pin Increases Switching Frequencies
(MAX1044)No-Load Supply Current: 200µA Max at 5VNo External Diode Required for Higher-Voltage
Operation
______________Ordering Information
Ordering Information continued at end of data sheet.* Contact factory for dice specifications.
MAX1044/ICL7660
Switched-Capacitor Voltage Converters
________________________________________________________________Maxim Integrated Products1
Call toll free 1-800-998-8800 for free samples or literature.19-4667; Rev 1; 7/94
_________________Pin Configurations
__________Typical Operating Circuit
MAX1044/ICL7660
Switched-Capacitor Voltage Converters_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(Circuit of Figure 1, V+ = 5.0V, LV pin = 0V, BOOST pin = open, ILOAD= 0mA, TA= TMINto TMAX, unless otherwise noted.)
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 1:The Maxim ICL7660 and MAX1044 can operate without an external output diode over the full temperature and voltage
ranges. The Maxim ICL7660 can also be used with an external output diode in series with pin 5 (cathode at VOUT) when
replacing the Intersil ICL7660. Tests are performed without diode in circuit.
Note 2:fOSCis tested with COSC= 100pF to minimize the effects of test fixture capacitance loading. The 1pF frequency is correlat-
ed to this 100pF test point, and is intended to simulate pin 7’s capacitance when the device is plugged into a test socket
with no external capacitor. For this test, the LV pin is connected to GND for comparison to the original manufacturer’s
device, which automatically connects this pin to GND for (V+ > 3V).
Supply Voltage (V+ to GND, or GND to VOUT)....................10.5V
Input Voltage on Pins 1, 6, and 7.........-0.3V ≤VIN≤(V+ + 0.3V)
LV Input Current ..................................................................20µA
Output Short-Circuit Duration (V+ ≤5.5V)..................Continuous
Continuous Power Dissipation (TA= +70°C)
Plastic DIP (derate 9.09mW/°C above +70°C)............727mW
SO (derate 5.88mW/°C above +70°C).........................471mW
µMAX(derate 4.1mW/°C above +70°C)......................330mW
CERDIP (derate 8.00mW/°C above +70°C).................640mW
TO-99 (derate 6.67mW/°C above +70°C)....................533mW
Operating Temperature Ranges
MAX1044C_ _ /ICL7660C_ _..............................0°C to +70°C
MAX1044E_ _ /ICL7660E_ _............................-40°C to +85°C
MAX1044M_ _ /ICL7660M_ _........................-55°C to +125°C
Storage Temperature Range............................-65°C to + 150°C
Lead Temperature (soldering, 10sec).............................+300°C
EFFICIENCY
vs. OSCILLATOR FREQUENCY
MAX1044-Fig 7
OSCILLATOR FREQUENCY (Hz)
EFFICIENCY (%)
1021036x105
10,000
100,000
OSCILLATOR FREQUENCY
vs. EXTERNAL CAPACITANCE
MAX1044-Fig 8
COSC (pF)
OSCILLATOR FREQUENCY (Hz)
1000100100,000
10,000
OSCILLATOR FREQUENCY
vs. SUPPLY VOLTAGE
MAX1044-Fig 9
SUPPLY VOLTAGE (V)
OSCILLATOR FREQUENCY (Hz)
10,000
100,000
OUTPUT VOLTAGE and OUTPUT RIPPLE
vs. LOAD CURRENT
MAX1044-Fig 1
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
OUTPUT RIPPLE (mVp-p)
OUTPUT VOLTAGE and OUTPUT RIPPLE
vs. LOAD CURRENT
MAX1044-Fig 2
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
OUTPUT RIPPLE (mVp-p)-1.5
OUTPUT VOLTAGE and OUTPUT RIPPLE
vs. LOAD CURRENT
MAX1044-Fig 3
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
OUTPUT RIPPLE (mVp-p)
EFFICIENCY and SUPPLY CURRENT
vs. LOAD CURRENT
MAX1044-Fig 4
LOAD CURRENT (mA)
EFFICIENCY (%)
SUPPLY CURRENT (mA)30510152025303540
EFFICIENCY and SUPPLY CURRENT
vs. LOAD CURRENTMAX1044-Fig 5
LOAD CURRENT (mA)
EFFICIENCY (%)
SUPPLY CURRENT (mA)30510152025303540
EFFICIENCY and SUPPLY CURRENT
vs. LOAD CURRENTMAX1044-Fig 6
LOAD CURRENT (mA)
EFFICIENCY (%)
SUPPLY CURRENT (mA)30
MAX1044/ICL7660
Switched-Capacitor Voltage Converters
_______________________________________________________________________________________3
__________________________________________Typical Operating Characteristics(V+ = 5V; CBYPASS = 0.1µF; C1 = C2 = 10µF; LV = open; OSC = open; TA= +25°C; unless otherwise noted.)
QUIESCENT CURRENT
vs. SUPPLY VOLTAGE
MAX1044-Fig 12
SUPPLY VOLTAGE (V)
QUIESCENT CURRENT (µA)
OUTPUT RESISTANCE
vs. OSCILLATOR FREQUENCY
MAX1044-Fig 14
FREQUENCY (Hz)
RESISTANCE (
QUIESCENT CURRENT
vs. TEMPERATURE
MAX1044-Fig 13
TEMPERATURE (°C)
QUIESCENT CURRENT (µA)
OUTPUT RESISTANCE
vs. SUPPLY VOLTAGE
MAX1044-Fig 15
SUPPLY VOLTAGE (V)
OUTPUT RESISTANCE (
OUTPUT RESISTANCE
vs. TEMPERATURE
MAX1044-Fig 16
TEMPERATURE (°C)
OUTPUT RESISTANCE (
MAX1044/ICL7660
Switched-Capacitor Voltage Converters_______________________________________________________________________________________
____________________________Typical Operating Characteristics (continued)(V+ = 5V; CBYPASS = 0.1µF; C1 = C2 = 10µF; LV = open; OSC = open; TA= +25°C; unless otherwise noted.)
OSCILLATOR FREQUENCY
vs. TEMPERATURE
MAX1044-Fig 10
TEMPERATURE (°C)
OSCILLATOR FREQUENCY (kHz)
1001011021031041055x105
QUIESCENT CURRENT
vs. OSCILLATOR FREQUENCYMAX1044-Fig 11
OSCILLATOR FREQUENCY (Hz)
QUIESCENT CURRENT (µA)
10,000
_______________Detailed DescriptionThe MAX1044/ICL7660 are charge-pump voltage con-
verters. They work by first accumulating charge in a
bucket capacitor and then transfer it into a reservoir
capacitor. The ideal voltage inverter circuit in Figure 2
illustrates this operation.
During the first half of each cycle, switches S1 & S3
close and switches S2 & S4 open, which connects the
bucket capacitor C1 across V+ and charges C1.
During the second half of each cycle, switches S2 & S4
close and switches S1 & S3 open, which connects the
positive terminal of C1 to ground and shifts the nega-
tive terminal to VOUT. This connects C1 in parallel with
the reservoir capacitor C2. If the voltage across C2 is
smaller than the voltage across C1, then charge flows
from C1 to C2 until the voltages across them are equal.
During successive cycles, C1 will continue pouring
charge into C2 until the voltage across C2 reaches
- (V+). In an actual voltage inverter, the output is less
than - (V+) since the switches S1–S4 have resistance
and the load drains charge from C2.
Additional qualities of the MAX1044/ICL7660 can be
understood by using a switched-capacitor circuit
model. Switching the bucket capacitor, C1, between
the input and output of the circuit synthesizes a resis-
tance (Figures 3a and 3b.)
When the switch in Figure 3a is in the left position,
capacitor C1 charges to V+. When the switch moves to
the right position, C1 is discharged to VOUT. The
charge transferred per cycle is: ΔQ = C1(V+ - VOUT). If
the switch is cycled at frequency f, then the resulting
MAX1044/ICL7660
Switched-Capacitor Voltage Converters
_______________________________________________________________________________________5
_____________________________________________________________Pin Description
MAX1044/ICL7660current is: I = f x ΔQ = f x C1(V+ - VOUT). Rewriting this
equation in Ohm’s law form defines an equivalent resis-
tance synthesized by the switched-capacitor circuit
where:
where f is one-half the oscillator frequency. This resis-
tance is a major component of the output impedance of
switched-capacitor circuits like the MAX1044/ICL7660.
As shown in Figure 4, the MAX1044/ICL7660 contain
MOSFET switches, the necessary transistor drive cir-
cuitry, and a timing oscillator.
________________Design InformationThe MAX1044/ICL7660 are designed to provide a
simple, compact, low-cost solution where negative or
doubled supply voltages are needed for a few low-
power components. Figure 5 shows the basic negative
voltage converter circuit. For many applications, only
two external capacitors are needed. The type of
capacitor used is not critical.
Proper Use of the Low-Voltage (LV) PinFigure 4 shows an internal voltage regulator inside the
MAX1044/ICL7660. Use the LV pin to bypass this
regulator, in order to improve low-voltage performance(V+ - V)
1 / (f x C1)1
f x C1
OUT
EQUIV
and
Switched-Capacitor Voltage Converters_______________________________________________________________________________________Figure 3a. Switched Capacitor Model
Figure 3b. Equivalent Circuit
