MAXIM MAX864EEE

19-0478; Rev 0; 3/96
Dual-Output Charge Pump with Shutdown
The MAX864 CMOS, charge-pump, DC-DC voltage
converter produces a positive and a negative output
from a single positive input, and requires only four
capacitors. The charge pump first doubles the input
voltage, then inverts the doubled voltage. The input
voltage ranges from +1.75V to +6.0V.
The internal oscillator can be pin-programmed from
7kHz to 185kHz, allowing the quiescent current, capacitor size, and switching frequency to be optimized. The
55Ω output impedance permits useful output currents
up to 20mA. The MAX864 also has a 1µA logic-controlled shutdown.
The MAX864 comes in a 16-pin QSOP package that
uses the same board area as a standard 8-pin SOIC.
For more space-sensitive applications, the MAX865 is
available in an 8-pin µMAX package, which uses half
the board area of the MAX864.
________________________Applications
Low-Voltage GaAsFET Bias in Wireless Handsets
VCO and GaAsFET Supply
____________________________Features
♦ Requires Only Four Capacitors
♦ Dual Outputs (Positive and Negative)
♦ Low Input Voltages: +1.75V to +6.0V
♦ 1µA Logic-Controlled Shutdown
♦ Selectable Frequencies Allow Optimization
of Capacitor Size and Supply Current
______________Ordering Information
PART
MAX864C/D
MAX864EEE
TEMP. RANGE
0°C to +70°C
-40°C to +85°C
PIN-PACKAGE
Dice*
16 QSOP
* Contact factory for dice specifications.
Split Supply from 2 to 4 Ni Cells or 1 Li+ Cell
Low-Cost Split Supply for Low-Voltage
Data-Acquisition Systems
Split Supply for Analog Circuitry
LCD Panels
__________Typical Operating Circuit
__________________Pin Configuration
VIN
(+1.75V TO +6.0V)
TOP VIEW
C1- 1
16 C1+
C2+ 2
15 V+
GND 3
14 N.C.
C2- 4
MAX864
V- 5
13 N.C.
IN
11 GND
FC1 7
10 N.C.
FC0 8
9
+2VIN
V-
-2VIN
C1+
C1-
MAX864
C2+
12 IN
SHDN 6
V+
C2FC0 FC1 SHDN GND
N.C.
VIN
VIN
VIN
QSOP
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
MAX864
_______________General Description
MAX864
Dual-Output Charge Pump with Shutdown
ABSOLUTE MAXIMUM RATINGS
V+ to GND ..............................................................-0.3V to +12V
SHDN, FC0, FC1 to GND .............................-0.3V to (V+ + 0.3V)
IN to GND ..............................................................-0.3V to +6.2V
V- to GND ...............................................................+0.3V to -12V
V- Output Current .............................................................100mA
V- Short Circuit to GND .................................................Indefinite
Operating Temperature Range
MAX864EEE......................................................-40°C to +85°C
Continuous Power Dissipation (TA = +70°C)
QSOP (derate 8.70mW/°C above +70°C) .....................696mW
Storage Temperature Range ............................ -65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+300°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.
ELECTRICAL CHARACTERISTICS (Note 1)
(VIN = 5V, SHDN = VIN, circuit of Figure 1, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
MIN
TYP
TA = +25°C
1.75
1.25
TA = TMIN to TMAX
2.00
MAX
UNITS
SUPPLY
Minimum Start-Up Voltage
RLOAD = 10kΩ
Maximum Supply Voltage
RLOAD = 10kΩ
Supply Current
Shutdown Current
Oscillator Frequency
V
6.0
FC1 = FC0 = GND, f = 7kHz
0.6
1.0
FC1 = GND, FC0 = IN, f = 33kHz
2.4
3.65
FC1 = IN, FC0 = GND, f = 100kHz
7
11
FC1 = FC0 = IN, f = 185kHz
12
18
FC1 = FC0 = IN or GND, SHDN = GND
V
mA
0.1
1
FC1 = FC0 = GND
5
7
10
µA
FC1 = GND, FC0 = IN
24
33
48
FC1 = IN, FC0 = GND
70
100
140
FC1 = FC0 = IN
130
185
260
2.2
1.0
V
1
µA
kHz
INPUTS AND OUTPUTS
Logic Input Low Voltage
SHDN, FC0, FC1
Logic Input High Voltage
SHDN, FC0, FC1
3.5
Logic Input Bias Current
SHDN, FC0 = FC1 = GND or IN
-1
V+ to IN Shutdown Resistance
IV+ = 10mA
22
100
Ω
V- to GND Shutdown Resistance
IV- = 10mA
6
50
Ω
55
75
Output Resistance
(Note 1)
IV+ = 10mA, IV- = 0mA
V+ = 10V, IV- = 10mA (forced)
Voltage Conversion Efficiency
TA = +25°C
2.8
TA = TMIN to TMAX
V
100
TA = +25°C
34
TA = TMIN to TMAX
50
Ω
60
V+, RL = ∞
95
99
V-, RL = ∞
95
99
%
Note 1: Measured using the capacitor values in Table 1. Capacitor ESR contributes approximately 10% of the output impedance
[ESR + 1 / (pump frequency x capacitance)].
2
_______________________________________________________________________________________
Dual-Output Charge Pump with Shutdown
EFFICIENCY vs. OUTPUT CURRENT
@ 33kHz PUMP FREQUENCY
V+
70
V-
VIN = 3.3V
V-
50
40
30
C1–C4 = 33µF
FC1 = 0, FC0 = 0
20
50
40
30
C1–C4 = 6.8µF
FC1 = 0, FC0 = 1
0
20
15
25
35
30
5
10
15
20
25
30
OUTPUT CURRENT (mA)
OUTPUT CURRENT (mA)
EFFICIENCY vs. OUTPUT CURRENT
@ 185kHz PUMP FREQUENCY
OUTPUT RESISTANCE
vs. SUPPLY VOLTAGE
V+
V+
70
60
VIN = 5.0V
V-
50
V-
40
30
C1–C4 = 1µF
FC1 = 1, FC0 = 1
20
160
0
10
20
15
25
30
FC1 = 1, FC0 = 1
(185kHz @ 5V)
140
ROUT100
ROUT+
80
15
20
25
30
MAX864-03
35
140
V-, VIN = 3.0V
125
V-, VIN = 4.5V
110
V+, VIN = 3.0V
95
80
65
V+, VIN = 4.5V
50
35
1.0
2.0
3.0
4.0
5.0
-55 -35 -15
6.0
5
25
45
65
85 105 125
OUTPUT CURRENT vs. PUMP CAPACITANCE
(VIN = 3.15V, V+ + V- = 10V)
MAX864-07
V- LOADED
4
BOTH V+ AND
V- LOADED EQUALLY
-2
C1–C4 = 1µF
VIN = 4.75V
FC1 = 1
FC0 = 1 (185kHz)
-4
V- LOADED
-6
-8
V+ LOADED
-10
4.5
f = 33kHz
4.0
3.5
f = 185kHz
3.0
f = 100kHz
f = 7kHz
2.5
2.0
1.5
1.0
0.5
C1 = C2 = C3 = C4
0
10
15
20
25
30
OUTPUT CURRENT (mA)
35
40
OUTPUT CURRENT FROM V+ TO V- (mA)
OUTPUT CURRENT vs. PUMP CAPACITANCE
(VIN = 1.9V, V+ + V- = 6V)
MAX864-08
OUTPUT VOLTAGE
vs. OUTPUT CURRENT
6
5
10
TEMPERATURE (°C)
V+ LOADED
0
5
SUPPLY VOLTAGE (V)
8
0
20
OUTPUT CURRENT (mA)
10
2
C1–C4 = 2.2µF
FC1 = 0, FC0 = 0
OUTPUT RESISTANCE
vs. TEMPERATURE
120
35
OUTPUT CURRENT FROM V+ TO V- (mA)
5
30
OUTPUT CURRENT (mA)
40
0
40
0
60
10
V-
V50
35
OUTPUT RESISTANCE (Ω)
VIN = 3.3V
VIN = 5.0V
0
0
MAX864-05
10
OUTPUT RESISTANCE (Ω)
80
5
MAX864-04
0
V+
60
10
10
0
EFFICIENCY V+, V- (%)
V-
20
10
OUTPUT VOLTAGE (V)
V-
60
V+
V+
V+
VIN = 5.0V
VIN = 3.3V
70
9
MAX864-09
60
70
80
MAX864-06
V+
80
EFFICIENCY V+, V- (%)
EFFICIENCY V+, V- (%)
VIN = 3.3V
80
EFFICIENCY V+, V- (%)
VIN = 5.0V
90
90
MAX864-01
100
EFFICIENCY vs. OUTPUT CURRENT
@ 100kHz PUMP FREQUENCY
MAX864-02
EFFICIENCY vs. OUTPUT CURRENT
@ 7kHz PUMP FREQUENCY
8
f = 100kHz
7
f = 33kHz
6
f = 185kHz
5
f = 7kHz
4
3
2
1
C1 = C2 = C3 = C4
0
0
5
10 15 20 25 30 35 40 45 50
PUMP CAPACITANCE (µF)
0
5
10 15 20 25 30 35 40 45 50
PUMP CAPACITANCE (µF)
_______________________________________________________________________________________
3
MAX864
__________________________________________Typical Operating Characteristics
(VIN = 5.0V, capacitor values in Table 1, TA = +25°C, unless otherwise noted.)
____________________________Typical Operating Characteristics (continued)
(VIN = 5.0V, capacitor values in Table 1, TA = +25°C, unless otherwise noted.)
OUTPUT VOLTAGE RIPPLE
vs. PUMP CAPACITANCE
(VIN = 1.9V, V+ + V- = 6V)
10
100kHz
185kHz
8
7kHz
6
4
2
C1 = C2 = C3 = C4
350
OUTPUT RIPPLE IS
MEASURED FOR THE
LOAD CURRENT INDICATED
IN THE "OUTPUT CURRENT
vs. PUMP CAPACITANCE"
GRAPH AT VIN = 1.9V.
300
250
200
150
33kHz
100kHz
100
5
185kHz
50
185kHz
33kHz
100
10 15 20 25 30 35 40 45 50
0
5
10 15 20 25 30 35 40 45 50
OUTPUT VOLTAGE RIPPLE
vs. PUMP CAPACITANCE
(VIN = 4.75V, V+ + V- = 16V)
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
300
200
5
33kHz
100kHz
185kHz
100
500
400
300
200
100
3.0
MAX864-15
MAX864-14
600
SHUTDOWN SUPPLY CURRENT (µA)
400
100kHz
200
PUMP CAPACITANCE (µF)
SHUTDOWN SUPPLY CURRENT (nA)
500
300
PUMP CAPACITANCE (µF)
C1 = C2 = C3 = C4
OUTPUT RIPPLE IS
MEASURED FOR THE
LOAD CURRENT INDICATED
IN THE "OUTPUT CURRENT
vs. PUMP CAPACITANCE"
GRAPH AT VIN = 4.75V.
7kHz
600
400
PUMP CAPACITANCE (µF)
800
700
C1 = C2 = C3 = C4
OUTPUT RIPPLE IS
MEASURED FOR THE
LOAD CURRENT INDICATED
IN THE "OUTPUT CURRENT
vs. PUMP CAPACITANCE"
7kHz GRAPH AT VIN = 3.15V.
500
0
0
10 15 20 25 30 35 40 45 50
MAX864-13
0
2.5
2.0
1.5
1.0
VIN = 5.0V
0.5
VIN = 3.3V
0
0
5
10 15 20 25 30 35 40 45 50
1.0
2.0
3.0
4.0
5.0
-55 -35 -15
6.0
5
25
45
65
PUMP CAPACITANCE (µF)
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
SUPPLY CURRENT vs. TEMPERATURE
(VIN = 3.3V)
SUPPLY CURRENT vs. TEMPERATURE
(VIN = 5V)
PUMP FREQUENCY
vs. TEMPERATURE
6
12
SUPPLY CURRENT (mA)
FC1 = 1, FC0 = 1
5
4
FC1 = 1, FC0 = 0
3
2
FC1 = 1, FC0 = 1
10
8
FC1 = 1, FC0 = 0
6
4
FC1 = 0, FC0 = 1
1
2
FC1 = 0, FC0 = 0
0
5
25
45
65
TEMPERATURE (°C)
85 105 125
85 105 125
FC1 = 1, FC0 = 1
160
140
120
FC1 = 1, FC0 = 0
100
80
60
FC1 = 0, FC0 = 1
40
FC1 = 0, FC0 = 1
FC1 = 0, FC0 = 0
20
FC1 = 0, FC0 = 0
0
-55 -35 -15
200
180
PUMP FREQUENCY (kHz)
14
MAX864-16
7
MAX864-17
0
MAX864-18
0
4
7kHz
600
0
0
OUTPUT VOLTAGE RIPPLE (mVp-p)
C1 = C2 = C3 = C4
MAX864-12
400
OUTPUT VOLTAGE RIPPLE (mVp-p)
12
OUTPUT VOLTAGE RIPPLE
vs. PUMP CAPACITANCE
(VIN = 3.15V, V+ + V- = 10V)
MAX864-11
33kHz
OUTPUT VOLTAGE RIPPLE (mVp-p)
14
MAX864-10
OUTPUT CURRENT FROM V+ TO V- (mA)
OUTPUT CURRENT vs. PUMP CAPACITANCE
(VIN = 4.75V, V+ + V- = 16V)
SUPPLY CURRENT (mA)
MAX864
Dual-Output Charge Pump with Shutdown
0
-55 -35 -15
5
25
45
65
TEMPERATURE (°C)
85 105 125
-55 -35 -15
5
25
45
65
TEMPERATURE (°C)
_______________________________________________________________________________________
85 105 125
Dual-Output Charge Pump with Shutdown
MAX864-19
TIME TO EXIT SHUTDOWN
+5V
0V
FC0 = FC1 = IN (185kHz), C1–C4 = 1µF
+10V
FC0 = FC1 = GND (7kHz), C1–C4 = 33µF
0V
-10V
1ms/div
_____________________Pin Description
PIN
NAME
FUNCTION
1
C1-
Negative Terminal of the Flying Boost
Capacitor
2
C2+
Positive Terminal of the Flying
Inverting Capacitor
3, 11
GND
Ground (connect pins 3 and 11 together)
4
C2-
5
V-
Output of the Inverting Charge Pump
SHDN
Active-Low Shutdown Input. With
SHDN low, the part is in shutdown
mode and its supply current is less
than 1µA. In shutdown mode, V+
connects to IN through a 22Ω switch,
and V- connects to GND through a
6Ω switch.
6
VCC IN
C1
Negative Terminal of the Flying
Inverting Capacitor
7
FC1
Frequency Select, MSB (see Table 1)
8
FC0
Frequency Select, LSB (see Table 1)
9, 10,
13, 14
N.C.
No Connect—no internal connection.
Connect these to ground to improve
thermal dissipation.
12
IN
Positive Power-Supply Input
15
V+
Output of the Boost Charge Pump
16
C1+
Positive Terminal of the Flying Boost
Capacitor
C2
+5V
1 C12
C2+
3
GND
4 C25 V6
SHDN
7
FC1
8
FC0
MAX864
C1+ 16
15
V+
N.C. 14
N.C.
13
V+ OUT
C3
IL+
IN 12
11
GND
10
N.C.
9
N.C.
RL+
RL-
C4
IL-
V- OUT
SEE TABLE 1 FOR CAPACITOR VALUES.
Figure 1. Test Circuit
_______________________________________________________________________________________
5
MAX864
____________________________Typical Operating Characteristics (continued)
(VIN = 5.0V, capacitor values in Table 1, TA = +25°C, unless otherwise noted.)
MAX864
Dual-Output Charge Pump with Shutdown
_______________Detailed Description
Charge-Pump Frequency
and Capacitor Selection
The MAX864 requires only four external capacitors to
implement a voltage doubler/inverter. These may be
ceramic or polarized capacitors (electrolytic or tantalum) with values ranging from 0.47µF to 100µF.
Figure 2a illustrates the ideal operation of the positive
voltage 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 (V IN).
During the second half cycle, switches S1 and S3
open, switches S2 and S4 close, and capacitor C1 is
level shifted upward by V IN volts. 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 from 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 2VIN by 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-channel devices.
a)
The MAX864 offers four different charge-pump frequencies. To select a desired frequency, define pins FC0 and
FC1 as shown in Table 1. Lower charge-pump frequencies produce lower average supply currents, while higher charge-pump frequencies require smaller capacitors.
Table 1 also lists the recommended charge-pump
capacitor values for each pump frequency. Using values larger than those recommended will have little
effect on the output current. Using values smaller than
those recommended will reduce the available output
current and increase the output ripple. To cut the output ripple in half, double the values of C3 and C4.
To maintain the lowest output resistance, use capacitors
with low effective series resistance (ESR). At each switching frequency, the charge-pump output resistance is a
function of C1, C2, C3, and C4’s ESR. Minimizing the
charge-pump capacitors’ ESR minimizes output resistance. Use ceramic capacitors for best results.
Table 1. Frequency Selection
FREQUENCY
(kHz)
CAPACITORS
C1–C4
(µF)
FC1
FC0
0
0
7
33
0
1
33
6.8
1
0
100
2.2
1
1
185
1
b)
V+
S1
C1+
V+
S2
S5
C2+
S6
GND
IN
C3
C1
IL+
RL+
C2
IL-
RL-
C4
S3
S4
S7
IN
GND
C1-
S8
V-
GND
C2-
Figure 2. Idealized Voltage Quadrupler: a) Positive Charge Pump; b) Negative Charge Pump
6
_______________________________________________________________________________________
Dual-Output Charge Pump with Shutdown
Shutdown
The MAX864 features a shutdown mode that reduces
the maximum supply current to 1µA over temperature.
The SHDN pin is an active-low TTL logic-level input. If
the shutdown feature is unused, connect SHDN to IN.
In shutdown mode, V+ connects to IN through a 22Ω
switch and V- connects to GND through a 6Ω switch.
VDROOP- = I V - x RS The droop of the positive supply (V DROOP+ ) is the
product of the current draw from the positive supply
(ILOAD+) and the source resistance of the positive converter (RS+), where ILOAD+ is the combination of IVand the external load on V+ (IV+):
(
)
VDROOP+ = ILOAD+ x RS+ = I V+ + I V - x RS+
Determine V+ and V- as follows:
V+ = 2VIN - VDROOP+
V - = (V+ - VDROOP )
= -(2VIN - VDROOP+ - VDROOP- )
The output resistances 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:
VRIPPLE =
1
2
ILOAD (1 / fPUMP ) (1 / CRESERVOIR )
where ILOAD is the load on either V+ or V-. For example, with an fPUMP of 33kHz and 6.8µF reservoir capacitors, the ripple is 26mV when I LOAD is 12mA.
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 Considerations
Theoretically, a charge-pump voltage multiplier can
approach 100% 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 capacitors are negligible.
For the MAX864, the energy loss per clock cycle is the
sum of the energy loss in the positive and negative
converters, as follows:
LOSSCYCLE = LOSSPOS + LOSSNEG
1
2


= C1  V + − 2 V + VIN 
2


1
2
2

+ C2  V + − V − 
2


where V+ and V- are the actual measured output voltages.
The average power loss is simply:
( )
( )
( )( )
( )
Resulting in an efficiency of:
PLOSS = LOSSCYCLE x fPUMP
(
η = Total Output Power / Total Output Power − PLOSS
)
There will be a substantial voltage difference between
(V+ - VIN) and VIN for the positive pump, and between
V+ and V- if the impedances of the pump capacitors
(C1 and C2) are large with respect to their respective
output loads.
Larger reservoir capacitor (C3 and C4) values will
reduce output ripple. Larger values of both pump and
reservoir capacitors will improve efficiency.
_______________________________________________________________________________________
7
MAX864
Charge-Pump Output
The MAX864 is not a voltage regulator: the output
source resistance of either charge pump is approximately 55Ω at room temperature (with VIN = 5V); and V+
and V- 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- increases, since Vis derived from V+. Treating each converter 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 converter (RS-):
MAX864
Dual-Output Charge Pump with Shutdown
__________Applications Information
Positive and Negative Converter
The most common application of the MAX864 is as a
dual charge-pump voltage converter that provides positive and negative outputs of two times a positive input
voltage for biasing analog circuitry (Figure 3). Select a
charge-pump frequency high enough so it does not
interfere with other circuitry, but low enough to maintain
low supply current. See Table 1 for the correct device
configuration.
VIN
(+1.75V TO +6.0V)
C1
1 C12
C2+
3
GND
4 C2-
C2
IN
SEE TABLE 1
Paralleling Devices
Paralleling multiple MAX864s reduces the output resistance of both the positive and negative converters
(Figure 4). The effective output resistance is the output
resistance of one device divided by the total number of
devices. Separate C1 and C2 charge-pump capacitors
are required for each MAX864, but the reservoir capacitors C3 and C4 can be shared.
5 V6
SHDN
7
FC1
8
FC0
MAX864
C1+ 16
15
V+
14
N.C.
13
N.C.
IN 12
11
GND
10
N.C.
9
N.C.
+2 x VIN
C3
C4
-2 x VIN
Figure 3. Positive and Negative Converter
8
_______________________________________________________________________________________
Dual-Output Charge Pump with Shutdown
MAX864
VIN
3.3µF
3.3µF
1
2
3.3µF
3
4
C1-
V+
C2+ MAX864
C1+
IN
C2V-
GND
8
1
7
2
6
5
3.3µF
3
4
C1C2+ MAX864
C2V-
V+
C1+
IN
GND
8
V+ OUT
7
3.3µF
6
VIN
5
GND
3.3µF
V- OUT
Figure 4. Paralleling Two MAX864s
Heavy Output Current Loads
When under heavy loads, where V+ is sourcing current
into V- (i.e., load current flows from V+ to V-, rather than
from supply to ground), do not allow the V- supply to
pull above ground. In applications where large currents
flow from V+ to V-, use a Schottky diode (1N5817)
between GND and V-, with the anode connected to
GND (Figure 5).
GND
11
Layout and Grounding
Good layout is important, primarily for good noise performance. To ensure good layout, mount all components as close together as possible, keep traces short
to minimize parasitic inductance and capacitance, and
use a ground plane. Connecting all N.C. pins to a
ground plane improves thermal dissipation.
MAX864
V-
5
Figure 5. High V- Load Circuit
_______________________________________________________________________________________
9
Dual-Output Charge Pump with Shutdown
MAX864
___________________Chip Topography
C1-
C2+
C1+
V+
GND
0.120"
(3.05mm)
C2VIN
GND
SHDN
FC1
FC0
0.080"
(2.03mm)
TRANSISTOR COUNT: 143
SUBSTRATE CONNECTED TO V+
10
______________________________________________________________________________________
Dual-Output Charge Pump with Shutdown
DIM
A
A1
A2
B
C
D
E
e
H
h
L
N
S
α
D
A
e
A1
B
S
E
INCHES
MILLIMETERS
MAX
MIN
MIN
MAX
0.068
0.061
1.55
1.73
0.004 0.0098 0.127
0.25
0.061
0.055
1.40
1.55
0.012
0.008
0.20
0.31
0.0075 0.0098
0.19
0.25
SEE VARIATIONS
0.157
0.150
3.81
3.99
0.25 BSC
0.635 BSC
0.244
0.230
5.84
6.20
0.016
0.010
0.25
0.41
0.035
0.016
0.41
0.89
SEE VARIATIONS
SEE VARIATIONS
8°
0°
0°
8°
H
h x 45°
α
A2
N
E
C
DIM PINS
D
S
D
S
D
S
D
S
16
16
20
20
24
24
28
28
INCHES
MILLIMETERS
MIN
MAX MIN
MAX
0.189 0.196 4.80
4.98
0.0020 0.0070 0.05
0.18
0.337 0.344 8.56
8.74
0.0500 0.0550 1.27
1.40
0.337 0.344 8.56
8.74
0.0250 0.0300 0.64
0.76
0.386 0.393 9.80
9.98
0.0250 0.0300 0.64
0.76
21-0055A
QSOP
QUARTER
SMALL-OUTLINE
PACKAGE
L
______________________________________________________________________________________
11
MAX864
________________________________________________________Package Information
MAX864
Dual-Output Charge Pump with Shutdown
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.
12 __________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600
© 1996 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.