MAX865EUA-T ,Compact, Dual-Output Charge PumpApplicationsMAX865C/D 0°C to +70°C DiceMAX865EUA -40°C to +85°C 8 μMAXLow-Voltage GaAsFET Bias in W ..
MAX865EUA-T ,Compact, Dual-Output Charge PumpFeaturesThe MAX865 is a CMOS charge-pump DC-DC convert-♦ 1.11mm-High μMAX Packageer in an ultra-sma ..
MAX865EUA-T ,Compact, Dual-Output Charge PumpApplicationsMAX865C/D 0°C to +70°C DiceMAX865EUA -40°C to +85°C 8 μMAXLow-Voltage GaAsFET Bias in W ..
MAX8660AETL+ ,High-Efficiency, Low-IQ, PMICs with Dynamic Voltage Management for Mobile ApplicationsApplications Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
MAX8660AETL+T ,High-Efficiency, Low-IQ, PMICs with Dynamic Voltage Management for Mobile ApplicationsPin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
MAX8660BETL+T ,High-Efficiency, Low-IQ, PMICs with Dynamic Voltage Management for Mobile ApplicationsTable of Contents (continued)Design Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
MB84256A-10LLP , CMOS 256K-BIT LOW POWER SRAM
MB84256A-10LPF , CMOS 256K-BIT LOW POWER SRAM
MB84VD21183EM-70PBS , Stacked MCP (Multi-Chip Package) FLASH MEMORY & SRAM CMOS
MB84VD21194EM-70PBS , Stacked MCP (Multi-Chip Package) FLASH MEMORY & SRAM CMOS
MB84VD22181FM-70PBS , 32M (X16) FLASH MEMORY & 4M (X16) STATIC RAM
MB84VD22182EE-90 ,32M (x 8/x16) FLASH MEMORY & 4M (x 8/x16) STATIC RAMFUJITSU SEMICONDUCTORDS05-50204-2EDATA SHEETStacked MCP (Multi-Chip Package) FLASH MEMORY & SRAMCMO ..
MAX865EUA/T-MAX865EUA+-MAX865EUA+T-MAX865EUA-T
Compact, Dual-Output Charge Pump
_______________General DescriptionThe MAX865 is a CMOS charge-pump DC-DC convert-
er in an ultra-small μMAX package. It produces positive
and negative outputs from a single positive input, and
requires only four capacitors. The charge pump first
doubles the input voltage, then inverts the doubled volt-
age. The input voltage ranges from +1.5V to +6.0V.
The internal oscillator is guaranteed to be between
20kHz and 38kHz, keeping noise above the audio
range while consuming minimal supply current. A 75Ω
output impedance permits useful output currents up to
20mA.
The MAX865 comes in a 1.11mm-high, 8-pin μMAX
package that occupies half the board area of a stan-
dard 8-pin SOIC. For a device with selectable frequen-
cies and logic-controlled shutdown, refer to the MAX864
data sheet.
________________________ApplicationsLow-Voltage GaAsFET Bias in Wireless Handsets
VCO and GaAsFET Supplies
Split Supply from 3 Ni Cells or 1 Li+ Cell
Low-Cost Split Supply for Low-Voltage
Data-Acquisition Systems
Split Supply for Analog Circuitry
LCD Panels
____________________________Features1.11mm-High μMAX PackageCompact: Circuit Fits in 0.08in2Requires Only Four CapacitorsDual Outputs (positive and negative)+1.5V to +6.0V Input Voltage20kHz (min) Frequency (above the audio range)
Compact, Dual-Output Charge PumpC1+
GNDV-
C2-
C2+
C1-
MAX865
MAXTOP VIEW
__________________Pin ConfigurationMAX865C1+
GNDGND
+VIN to ±2VIN CONVERTER GND
C1-
C2+
C2-
+2*VIN
VIN
(+1.5V to +6.0V)
-2*VIN
__________Typical Operating Circuit19-0472; Rev 1; 7/97
PARTMAX865C/D
MAX865EUA-40°C to +85°C
0°C to +70°C
TEMP. RANGEPIN-PACKAGEDice
8 μMAX
______________Ordering Information
EFFICIENCY vs. OUTPUT CURRENT
(VIN = 5V)
AX865-01
OUTPUT CURRENT (mA)
(%61214
V-
V+
EFFICIENCY vs. OUTPUT CURRENT
(VIN = 3.3V)
AX865-02
OUTPUT CURRENT (mA)
(%56
V-
EFFICIENCY vs. OUTPUT CURRENT
(VIN = 2V)
MAX865-03
OUTPUT CURRENT (mA)
(%
V-
V+
__________________________________________Typical Operating Characteristics(Circuit of Figure 1, VIN= 5V, TA= +25°C, unless otherwise noted.)
Compact, Dual-Output Charge Pump
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VIN= 5V, C1 = C2 = C3 = C4 = 3.3μF, TA= TMINto TMAX, unless otherwise noted. Typical values are at TA= +25°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.
V+ to GND.................................................................+12V, -0.3V
IN to GND.................................................................+6.2V, -0.3V
V- to GND..................................................................-12V, +0.3V
V- Output Current .............................................................100mA
V- Short-Circuit to GND ................................................Indefinite
Continuous Power Dissipation (TA= +70°C)
μMAX (derate 4.1mW/°C above +70°C).......................330mW
Operating Temperature Range
MAX865EUA.....................................................-40°C to +85°C
Storage Temperature Range.............................-65°C to +160°C
Lead Temperature (soldering, 10sec).............................+300°C= +25°C
RLOAD= 10kΩ
RLOAD= 10kΩ= 5mA
V+ = 10V (forced),
IV-= 1mA
IV+= 1mA,
IV-= 0mA= -40°C to +85°C (Note 1)= +25°C= -40°C to +85°C (Note 1)
CONDITIONS0.61.056.0Maximum Supply Voltage2.01.5Minimum Supply Voltage85Power Efficiency
Output Resistance75100
2801.15Supply Current
19.52432.5kHz1834Oscillator Frequency
UNITSMINTYPMAXPARAMETER= +25°C= TMINto TMAX= +25°C= TMINto TMAX
V-, RL= ¥
V+, RL= ¥%9098Voltage Conversion Efficiency9599
Note 1:These specifications are guaranteed by design and are not production tested.
Compact, Dual-Output Charge PumOUTPUT VOLTAGE vs.
OUTPUT CURRENT
MAX865-04
OUTPUT CURRENT (mA)
, V
, V
- (V810
V-
C1 = C2 = C3 = C4 = 3.3mF
VIN = 4.75V
BOTH V+ AND
V- LOADED EQUALLY
V+
V+
OUTPUT VOLTAGE RIPPLE
vs. PUMP CAPACITANCE
AX865-05
PUMP CAPACITANCE (mF)10153035
C1 = C2 = C3 = C4E
A: V+, IN = 4.75V, V+ + |V-| = 16VV+, IN = 3.15V, V+ + |V-| = 10VV+, IN = 1.90V, V+ + |V-| = 6VV-, IN = 4.75V, V+ + |V-| = 16VV-, IN = 3.15V, V+ + |V-| = 10VV-, IN = 1.90V, V+ + |V-| = 6V202550
OUTPUT CURRENT
vs. PUMP CAPACITANCEAX865-06
PUMP CAPACITANCE (mF)
, V
- (m1015303545
VIN = 4.75V, V+ + |V-| = 16V
C1 = C2 = C3 = C4
VIN = 3.15V, V+ + |V-| = 10V
VIN = 1.90V, V+ + |V-| = 6V
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
AX865-07
SUPPLY VOLTAGE (V)
(m
C1 = C2 = C3 = C4 = 3.3mF
OUTPUT RESISTANCE
vs. TEMPERATURE
AX865-08
TEMPERATURE (°C)
(W
C1 = C2 = C3 = C4 = 3.3mF
V-, VIN = 3.3V
V+, VIN = 3.3V
V+, VIN = 5.0V
V-, VIN = 5.0V
PUMP FREQUENCY
vs. TEMPERATURE
AX865-09
TEMPERATURE (°C)
(k
C1 = C2 = C3 = C4 = 3.3mF
VIN = 5.0V
VIN = 3.3V
VIN = 2.0V
OUTPUT RESISTANCE
vs. SUPPLY VOLTAGE
MAX865-10
SUPPLY VOLTAGE (V)
(W
C1 = C2 = C3 = C4 = 3.3mF
____________________________Typical Operating Characteristics (continued)(Circuit of Figure 1, VIN= 5V, TA= +25°C, unless otherwise noted.)
_____________________Pin Description
NAMEFUNCTIONC1-Negative Terminal of the Flying Boost
CapacitorC2+Positive Terminal of the Flying
Inverting Capacitor
PINC2-Negative Terminal of the Flying
Inverting CapacitorV-Output of the Inverting Charge PumpC1+Positive Terminal of the Flying Boost
CapacitorV+Output of the Boost Charge PumpINPositive Power-Supply InputGNDGround
MAX865
C1+C1-
3.3mF
3.3mF
3.3mF
3.3mF
VIN
C2+
C2-
OUT+
OUT-
RL-
RL+
IV+
GND
IV-
Figure 1. Test Circuit
Compact, Dual-Output Charge Pump
____________________________Typical Operating Characteristics (continued)(Circuit of Figure 1, VIN= 5V, TA= +25°C, unless otherwise noted.)
10ms/div
VIN = 4.75V, 1mA LOAD
OUTPUT RIPPLE
(C1 = C2 = C3 = C4 = 1mF)V- OUTPUT
20mV/div
V+ OUTPUT
50mV/div
10ms/div
VIN = 4.75V, 1mA LOAD
OUTPUT RIPPLE
(C1 = C2 = C3 = C4 = 3.3mF)V- OUTPUT
10mV/div
V+ OUTPUT
10mV/div
Compact, Dual-Output Charge Pum
_______________Detailed DescriptionThe MAX865 contains all the circuitry needed to imple-
ment a voltage doubler/inverter. Only four external
capacitors are needed. These may be polarized elec-
trolytic or ceramic capacitors with values ranging from
1μF to 100μF.
Figure 2a shows the ideal operation of the positive volt-
age doubler. The on-chip oscillator generates a 50%
duty-cycle clock signal. During the first half cycle,
switches S2 and S4 open, switches S1 and S3 close,
and capacitor C1 charges to the input voltage (VIN).
During the second half cycle, switches S1 and S3
open, switches S2 and S4 close, and capacitor C1 is
level shifted upward by VIN. Assuming ideal switches
and no load on C3, charge transfers into C3 from C1
such that the voltage on C3 will be 2VIN, generating the
positive supply output (V+).
Figure 2b illustrates the ideal operation of the negative
converter. The switches of the negative converter are
out of phase with the positive converter. During the
second half cycle, switches S6 and S8 open and
switches S5 and S7 close, charging C2 from V+
(pumped up to 2VINby the positive charge pump) to
GND. In the first half of the clock cycle, switches S5
and S7 open, switches S6 and S8 close, and the
charge on capacitor C2 transfers to C4, generating the
negative supply. The eight switches are CMOS power
MOSFETs. Switches S1, S2, S4, and S5 are P-channel
devices, while switches S3, S6, S7, and S8 are N-chan-
nel devices.
Charge-Pump OutputThe MAX865 is not a voltage regulator: the output
source resistance of either charge pump is approxi-
mately 150Ωat room temperature with VIN= +5V, and
V+ and V- will approach +10V and -10V, respectively,
when lightly loaded. Both V+ and V- will droop toward
GND as the current draw from either V+ or V- increas-
es, since V- is derived from V+. Treating each convert-
er separately, the droop of the negative supply
(VDROOP-) is the product of the current draw from V-
(IV-) and the source resistance of the negative convert-
er (RS-):
The droop of the positive supply (VDROOP+) is the
product of the current draw from the positive supply
(ILOAD+) and the source resistance of the positive
b)C1+C3
C1-S6S8
C2-
GND
RL-
RL+
C2+
GNDIN
IV-
GND
IV+V+
Figure 2. Idealized Voltage Quadrupler: a) Positive Charge Pump; b) Negative Charge Pump = I x RS-DROOP-V-
converter (RS+), where ILOAD+is the combination of IV-
and the external load on V+ (IV+):
Determine V+ and V- as follows:
The output resistance for the positive and negative
charge pumps are tested and specified separately. The
positive charge pump is tested with V- unloaded. The
negative charge pump is tested with V+ supplied from
an external source, isolating the negative charge
pump.
Current draw from either V+ or V- is supplied by the
reservoir capacitor alone during one half cycle of the
clock. Calculate the resulting ripple voltage on either
output as follows:
where ILOADis the load on either V+ or V-. For the typi-
cal fPUMPof 30kHz with 3.3μF reservoir capacitors, the
ripple is 25mV when ILOADis 5mA. Remember that, in
most applications, the total load on V+ is the V+ load
current (IV+) and the current taken by the negative
charge pump (IV-).
Efficiency ConsiderationsTheoretically, a charge-pump voltage multiplier can
approach 100% power efficiency under the following
conditions:The charge-pump switches have virtually no offset
and extremely low on-resistance.The drive circuitry consumes minimal power. The impedances of the reservoir and pump capaci-
tors are negligible.
For the MAX865, the energy loss per clock cycle is the
sum of the energy loss in the positive and negative
converters, as follows:
The average power loss is simply:
Resulting in an efficiency of:
MAX865
C1+1
C1-
GND
3.3mF
3.3mF
3.3mF3.3mF
3.3mF3.3mF
OUT+
IN
OUT-
C2-
C2-
GND
MAX865
C1+1
C1-8
C2+
C2-
VIN
GND
Figure 3. Paralleling MAX865s
Compact, Dual-Output Charge Pump = I x RS+=I+ I x RS+DROOP+LOAD+V+V-() = LOSS x fLOSSCYCLEPUMP=-()TotalOutputPowerTotalOutputPowerPLOSS / = I (1 / f) (1 / C)RIPPLELOADPUMPRESERVOIR = 2V - V = (V+ - V)=-(2V-V-V)DROOP+
DROOPINDROOP+DROOP-
LOSS = LOSS+ LOSS
= C1
CYCLEPOSNEGVVVV+()-+()()Ø+()--()Ø2
