Rainbow Electronics MAX768 User Manual

19-1174; Rev 0; 12/96
Low-Noise, Dual-Output, Regulated Charge Pump
for GaAsFET, LCD, and VCO Supplies
_______________General Description
The MAX768 low-noise, dual-output, regulated charge pump provides a negative output for biasing GaAsFET power amplifiers, and a positive output for powering voltage-controlled oscillators (VCOs) in wireless hand­sets. The outputs can also be used to power LCDs. Output ripple is less than 2mVp-p. The MAX768 is intended for use in low-voltage systems where a simple charge-pump inverter is inadequate, or where the VCO needs more range to improve its signal-to-noise ratio. The input range is 2.5V to 5.5V, enabling direct power from 1Li+ and 3-cell NiMH/NiCd batteries.
The MAX768 includes a voltage-doubler charge pump, followed by an inverting charge pump. This combina­tion produces unregulated outputs that are ±2x the input. Two internal low-dropout linear regulators provide the low-noise, regulated positive and negative outputs. Output current is guaranteed to be at least 5mA per output. The linear regulators use CMOS devices, so the quiescent current remains independent of output load­ing (even in dropout), and the dropout voltage approaches zero with no load current.
The MAX768 has two preset switching frequencies (25kHz or 100kHz), or can be synchronized by an exter­nal clock from 20kHz to 240kHz. This flexibility permits users to optimize their designs based on noise, capaci­tor size, and quiescent-supply-current criteria.
The device features Dual Mode™ operation: the output voltage is preset to +5V and -5V, or can be adjusted by adding external resistor dividers. Other features include independent shutdowns and a logic output that signals when the negative voltage has risen to within 10% of its regulation setpoint (to protect the power amplifier GaAsFET). The MAX768 is available in a space-saving, 16-pin QSOP, which is the same size as a standard 8-pin SO.
________________________Applications
GaAsFET Power Amp Bias Voltage-Controlled Oscillator (VCO) Supply Tuner Diode Power Supply Positive and Negative LCD Supply Cellular Phone PCS and Cordless Phone Wireless Handsets Wireless Handheld Computers Wireless PCMCIA Cards Modems
____________________________Features
Dual Positive/Negative Regulated Outputs:
±5V
Output-Ready Indicator to Protect GaAsFET PAs2.5V to 5.5V Input Voltage RangeLow-Noise Output Ripple: < 2mVp-pSynchronizable Switching FrequencyUses Only Small, Low-Cost Capacitors0.1µA Independent Shutdown ControlsAdjustable Output VoltagesSmall 16-Pin QSOP Package
OUT
from 3V
IN
______________Ordering Information
PART
MAX768C/D MAX768EEE -40°C to +85°C
*
Dice are specified at TA= +25°C, DC parameters only.
Pin Configuration appears at end of data sheet.
Dual Mode is a trademark of Maxim Integrated Products.
TEMP. RANGE PIN-PACKAGE
0°C to +70°C
Dice*
16 QSOP
__________Typical Operating Circuit
VIN
(3.0V TO 5.5V)
C7
C5
C6
POSITIVE OUTPUT +5V
NEGATIVE OUTPUT
-5V OUTPUT-
READY SIGNAL
SYNC PSHDN NSHDN C1+
C1
C2
C1­C2+
C2-
IN
MAX768
GND
POUT
V+
C3
C4
V-
NOUT
RDY
SETPSETN
MAX768
________________________________________________________________
Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
Low-Noise, Dual-Output, Regulated Charge Pump for GaAsFET, LCD, and VCO Supplies
ABSOLUTE MAXIMUM RATINGS
VIN, C1-, SYNC, PSHDN, NSHDN to GND...............-0.3V to +6V
V+, C1+, C2+, RDY to GND...................................-0.3V to +12V
SETP to GND .......................................................... -0.3V to +3V
SETN to GND............................................................-3V to +0.3V
V-, C2- to GND ...................................................... -12V to +0.3V
OUTP, OUTN Short Circuited to GND .......................Continuous
NOUT to V- ........................................................... -0.3V to +12V
MAX768
POUT to V+ ........................................................... -12V to +0.3V
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.
Continuous Power Dissipation (T
QSOP (derate 8.70mW/°C above +70°C)......................696mW
Operating Temperature Range
MAX768EEE.......................................................-40°C to +85°C
Maximum Junction Temperature .....................................+150°C
Storage Temperature Range.............................-65°C to +165°C
Lead Temperature (soldering, 10sec).............................+300°C
ELECTRICAL CHARACTERISTICS
(VIN= +3V, SYNC = IN, SETN = SETP = GND, NSHDN = PSHDN = IN, TA= -40°C to +85°C, unless otherwise noted. Typical values
= +25°C. See Figure 2.) (Note 1)
are at T
A
CONDITIONS
I
Minimum Input Start-Up Voltage
No-Load Supply Current at 100kHz (both regulators active)
No-Load Supply Current at 100kHz (negative regulator off)
No-Load Supply Current at 25kHz (both regulators active)
Dropout Voltage (2 x VIN- |V
Output Voltage Noise
SHUTDOWN
SHDN Input Bias Current
OUT
)
|
= 0
LOAD
0mA < I 0mA < I (Note 2) (Note 3) VIN= 3V, V VIN= 3.0V VIN= 5.5V 1.5
NSHDN = GND
V
SYNC
2 x VIN- | V VIN= 3V to 5.5V
I
POUT
I
NOUT
C
POUT =CNOUT
10kHz < f < 1MHz
V
SHDN
NSHDN = PSHDN = SYNC = GND
< 5mA, VIN= 3.0V to 5.5V V4.81 5.00 5.14Positive Output Voltage
LOAD
< 5mA, VIN= 3.0V to 5.5V
LOAD
4.81V, V
POUT
= GND mA0.45 0.80
I
POUT
OUT
|
I
POUT
= 0mA to 5mA, = 0mA to -5mA
=
10µF,
= 3V
NOUT
= I = I
NOUT NOUT
POUT NOUT
-4.82V
= 0.1mA = 5mA
= +70°C)
A
0.8 1.4
20
420 900
1.2
1.7
UNITSMIN TYP MAXPARAMETER
%/mA0.06 0.12Load Regulation
mVp-p
V3.0 5.5Input Voltage Range V2.5
V-5.10 -5.00 -4.82Negative Output Voltage V1.25 11Positive Output Voltage Adjustable Range V-11 -1.25Negative Output Voltage Adjustable Range
mA5Maximum POUT, NOUT Output Currents mA
mA0.3
mV
%/V-0.12 0.0 0.12Line Regulation
V0.4Shutdown/SYNC Logic-Low Input Threshold V2.0Shutdown/SYNC Logic-High Input Threshold
µA0.1 2 µA0.1 10Shutdown Supply Current
2 _______________________________________________________________________________________
Low-Noise, Dual-Output, Regulated Charge Pump
RDY
for GaAsFET, LCD, and VCO Supplies
ELECTRICAL CHARACTERISTICS (continued)
(VIN= +3V, SYNC = IN, SETN = SETP = GND, NSHDN = PSHDN = IN, TA= -40°C to +85°C, unless otherwise noted. Typical values
= +25°C. See Figure 2.) (Note 1)
are at T
A
CONDITIONS
SYNC
Oscillator Frequency (internal)
SYNC = GND (divide by 4) V
= 3V
SYNC
SET INPUT
Positive Set-Reference Voltage
Negative Set-Reference Voltage
I
POUT
I
NOUT
V
SETP
= 0.1mA
= 0.1mA
= V
SETN
TA= +25°C TA= -40°C to + 85°C TA= +25°C TA= -40°C to + 85°C
= 1.3V
OUTPUT
RDY Output Threshold
Percent of V I
= 2mA V0.25Output Low Voltage
SINK
V
= 10V
RDY
NOUT
, I
NOUT
= 5mA
Note 1: Parameters to -40°C are guaranteed by design, not production tested. Note 2: Maximum output voltage range is from the positive reference voltage to 2 x V Note 3: Maximum output voltage range is from the negative reference voltage to -2 x V
21.5 25 28.5 85 100 115
1.217 1.25 1.283
1.215 1.25 1.285
-1.270 -1.25 -1.230
-1.275 -1.25 -1.225
- dropout voltage.
IN
+ dropout voltage.
IN
UNITSMIN TYP MAXPARAMETER
MAX768
kHz20 240SYNC Frequency Range (external)
%40 60SYNC Duty Cycle (external)
kHz
µA0.1 2SYNC Input Leakage Current
V
V
µA0.01 0.1SETP, SETN Input Leakage Current
%85 94 98
µA0.01 2Output Off Current
mA10Maximum Sink Current
__________________________________________Typical Operating Characteristics
(SYNC = IN, TA = +25°C, unless otherwise noted.)
mV
OUTPUT VOLTAGE
RMS
0.30
)
RMS
0.20
0.10
OUTPUT VOLTAGE (mV
0
vs. OUTPUT CURRENT
IN = 3.0V
NOUT = -5V
POUT = +5V
0 5 15 25
10 20
OUTPUT CURRENT (mA)
_______________________________________________________________________________________ 3
5.2
MAX768-TOC01
5.0
4.8
4.6
4.4
OUTPUT VOLTAGE (V)
4.2
4.0
POUT OUTPUT VOLTAGE 
vs. OUTPUT CURRENT
ONLY POUT LOADED
0 5 15 30
10 20 25
OUTPUT CURRENT (mA)
IN = 4.0V
IN = 3.0V
-4.2
-4.3
MAX768-TOC02
-4.4
-4.5
-4.6
-4.7
OUTPUT VOLTAGE (V)
-4.8
-4.9
-5.0
NOUT OUTPUT VOLTAGE vs. 
OUTPUT CURRENT
ONLY NOUT LOADED
0 5 15 30
OUTPUT CURRENT (mA)
IN = 3.0V
IN = 4.0V
10 20 25
MAX768-TOC03
Low-Noise, Dual-Output, Regulated Charge Pump for GaAsFET, LCD, and VCO Supplies
____________________________Typical Operating Characteristics (continued)
(SYNC = IN, TA = +25°C, unless otherwise noted.)
4
MAX768
3
2
SUPPLY CURRENT (mA)
1
0
0 40 120 320
SHDN SUPPLY CURRENT
20
vs. SYNC FREQUENCY
18 16 14 12 10
SHDN SUPPLY CURRENT (µA)
90 80 70 60 50 40
EFFICIENCY (%)
30 20 10
0
V
IN
8 6
4 2 0
-40 -15 35 85
EFFICIENCY vs. LOAD CURRENT
(NOUT ONLY LOADED)
V
IN
0.1 1 10 100 LOAD CURRENT (mA)
SUPPLY CURRENT
VIN = 5.0V
V
= 3.3V
IN
16080 200 240 280
SYNC FREQUENCY (kHz)
vs. TEMPERATURE
= 5.0V
V
= 3.3V
IN
TEMPERATURE (°C)
= 3.0V
V
= 4.0V
IN
CHARGE-PUMP FREQUENCY
115
100
MAX768-TOC04
85
70
55
40
CHARGE-PUMP FREQUENCY (kHz)
25
10
0.40
0.35
MAX768-TOC07
0.30
0.25
0.20
0.15
0.10
SHDN SUPPLY CURRENT (µA)
0.05 0
MAX768 TOC10
EFFICIENCY (%)
-0.05
90 80 70 60 50 40 30 20 10
0
6010
vs. SUPPLY VOLTAGE
SYNC = IN
SYNC = GND
2.5 3.0 4.0 6.0
SHDN SUPPLY CURRENT
-40 -15 35 85
EFFICIENCY vs. OUTPUT CURRENT
(POUT ONLY LOADED)
V
IN
0.1 1 10 100 OUTPUT CURRENT (mA)
4.53.5 5.0 5.5
SUPPLY VOLTAGE (V)
vs. TEMPERATURE
V
IN
TEMPERATURE (°C)
= 3.0V
V
= 4.0V
IN
= 5.0V
V
IN
V
IN
= 4.0V = 3.3V
6010
120
MAX768-TOC05
100
CHARGE-PUMP FREQUENCY (kHz)
MAX768-TOC08
SUPPLY CURRENT (mA)
MAX768 TOC11
EFFICIENCY (%)
CHARGE-PUMP FREQUENCY
vs. TEMPERATURE
V
= 3.3V
IN
SYNC = IN
80
60
40
20
0
-55 -35 5 125
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2 0
2.5 3.0 4.0 6.0
90 80 70 60 50 40 30 20 10
0
0.1 1 10 100
SYNC = GND
25-15 45 8565 105
TEMPERATURE (°C)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE (NO LOAD)
f = 100kHz
f = 25kHz
SUPPLY VOLTAGE (V)
EFFICIENCY vs. OUTPUT CURRENT
LOAD BETWEEN POUT AND NOUT
V
= 3.0V
IN
OUTPUT CURRENT (mA)
5.04.5 5.53.5
V
= 4.0V
IN
MAX768-TOC06
MAX768-TOC09
MAX768 TOC12
4 _______________________________________________________________________________________
Low-Noise, Dual-Output, Regulated Charge Pump
for GaAsFET, LCD, and VCO Supplies
_____________________________Typical Operating Characteristics (continued)
(SYNC = IN, TA = +25°C, unless otherwise noted.)
POUT MAXIMUM OUTPUT CURRENT 
140
120
100
80
60
40
MAXIMUM OUTPUT CURRENT (mA)
20
0
vs. SUPPLY VOLTAGE
ONLY POUT LOADED
2.5 3.0 4.0 SUPPLY VOLTAGE (V)
MAX768-TOC13
5.04.53.5
TIME TO EXIT SHUTDOWN
NOUT MAXIMUM OUTPUT CURRENT 
vs. SUPPLY VOLTAGE
90
ONLY NOUT LOADED
80 70 60 50 40 30
20
MAXIMUM OUTPUT CURRENT (mA)
10
0
2.5 3.0 4.0 5.0
MAX768-TOC15
SUPPLY VOLTAGE (V)
+3V,
PSHDN = NSHDN
+5V, V
POUT
0V
MAX768-TOC14
4.53.5
MAX768
-5V, V
NOUT
0V,
RDY
1ms/div
POUT OUTPUT NOISE AND RIPPLE
POUT = +5V AT 5mA IN = 3.0V
500µs/div
MAX768-TOC16
V
500µV/div
POUT,
AC COUPLED
NOUT OUTPUT NOISE AND RIPPLE
NOUT = -5V AT 5mA IN = 3.0V
500µs/div
_______________________________________________________________________________________ 5
MAX768-TOC17
V
, 500µV/div
NOUT
AC COUPLED
Low-Noise, Dual-Output, Regulated Charge Pump for GaAsFET, LCD, and VCO Supplies
______________________________________________________________Pin Description
PIN
MAX768
NAME FUNCTION
1 C1- Negative Terminal of the Doubler Charge-Pump Capacitor. See Table 2 for capacitor selection. 2 GND Ground 3 C2- Negative Terminal of the Inverter Charge-Pump Capacitor 4 V- Inverter Charge-Pump Output. See Table 2 for capacitor selection. 5 NOUT Negative Regulator Output. See Table 2 for capacitor selection.
6 SETN
7
NSHDN
8
PSHDN
9 SYNC
10
11 SETP 12 POUT Positive Regulator Output. See Table 2 for capacitor selection.
13 V+ Doubler Charge-Pump Output. See Table 2 for capacitor selection. 14 C1+ Positive Terminal of the Doubler Charge-Pump Capacitor. See Table 2 for capacitor selection. 15 IN Supply (3V to 5.5V). Bypass IN with 4.7µF to GND. 16 C2+ Positive Terminal of the Inverter Charge-Pump Capacitor. See Table 2 for capacitor selection.
RDY
Set Negative Output Voltage Input. Connect SETN to GND for factory-preset -5V. Connect a resistor divider between NOUT, SETN, and GND for custom output voltage setting.
Negative-Supply Shutdown Input. Pull NSHDN low to turn off the inverting charge pump, the negative reg­ulator, and the bias-ready indicator. If PSHDN is also low, the part completely shuts down.
Positive-Supply Shutdown Input. Pull PSHDN low to turn off the positive regulator. If NSHDN is also low, the part completely shuts down.
Clock Synchronizing Input. Connect an external 20kHz f MAX768 to that frequency. Connect SYNC to GND to select the internal 25kHz clock, or to IN for the inter­nal 100kHz clock.
Output-Ready Indicator. This open-drain output pulls to GND when the negative output voltage (NOUT) is within 10% of the regulation voltage.
Set Positive Output Voltage Input. Connect SETP to GND for factory-preset +5V output. Connect a resistor divider between POUT, SETP, and GND for custom output voltage setting.
240kHz to SYNC to synchronize the
CLK
6 _______________________________________________________________________________________
Low-Noise, Dual-Output, Regulated Charge Pump
for GaAsFET, LCD, and VCO Supplies
IN
V+
P
POUT
MAX768
C1+
VOLTAGE  DOUBLER
C1-
SHDN
Figure 1. Functional Diagram
PSHDN
SYNC
NSHDN
C2+
C2-
VOLTAGE  INVERTER
V-
_______________Detailed Description
The MAX768 requires only seven external capacitors to implement a regulated voltage doubler/inverter. These can be ceramic or polarized electrolytic capacitors rang­ing from 2.2µF to 47µF. Figure 1 is a functional diagram of the MAX768. The applied input voltage (VIN) is first dou­bled to a value of 2VINby a capacitor charge pump and then stored in the V+ reservoir capacitor. Next, the volt­age at V+ is inverted to -2VINand stored at the V- reser­voir capacitor. The voltages at V+ and V- are then linear regulated and appear at POUT and NOUT, respectively. The ripple noise induced by the doubling and inverting charge pump is reduced by the linear regulators to
1.2mVp-p for POUT and 1.7mVp-p for NOUT. In addition, the linear regulator’s excellent AC rejection attenuates noise from the incoming supply. A minimum of 5mA is available at each output. When NOUT is more negative than 90% of the regulated output voltage, the open-drain RDY output pulls to GND.
The charge pump operates in three modes: when SYNC = GND, the charge pump operates at 25kHz; when SYNC = IN, it operates at 100kHz, or SYNC can be over- driven with an external clock in the 20kHz to 240kHz range. The clock must have a 40% to 60% duty cycle.
MAX768
SETP
+1.25V
REF
-1.25V
N
CONNECT TO GND TO SET V
GND
N
RDY
SETN CONNECT TO GND
TO SET V
NOUT
POUT
NOUT
= +5V
= -5V
__________Applications Information
Connect SETP or SETN directly to GND to select a fixed +5V or -5V output voltage, respectively (Figure 2). Select an alternative voltage for either output by con­necting SETP or SETN to the midpoint of a resistor volt­age divider from POUT or NOUT, respectively, to GND (Figure 3). (2 x VIN) must be 1.0V above the absolute value of the output voltage to ensure proper regulation. Calculate the output voltage from the formulas below. Choose R1 and R3 at between 100kto 400k.
where V
PSET REF
V
NSET REF
= -1.25V (typical).
Setting the Output Voltage
R2 = R1
()
R4 = R3
()
V
POUT
V
PSET REF
V
V
NSET REF
NOUT
1
 
1
 
= 1.25V (typical) and
_______________________________________________________________________________________ 7
Low-Noise, Dual-Output, Regulated Charge Pump
PSHDN
NSHDN
for GaAsFET, LCD, and VCO Supplies
Table 1. Shutdown-Control Logic
POUT
MAX768
Positive output active11
Positive output inactive10
STATUS
Table 2. Charge-Pump Capacitor Selection (Figure 2)
NOUT
STATUS
Negative output active Negative output inactive 0.7Positive output active01 Negative output active 0.3 Shutdown (low-power mode) 0.0001Shutdown (low-power mode)00
SUPPLY
CURRENT
(mA)
0.8
SYNC
INPUT
FREQUENCY
(kHz)
25GND
100IN
20 to 240External Clock
C1, C2, C3, C4 C5, C6 C7
10µF
2.2µF
C = 220µF/f (kHz)
Shutdown
The MAX768 has two active-low, TTL logic-level shut­down inputs: PSHDN and NSHDN. When both inputs are pulled low, the MAX768 shuts down and the supply current is reduced to 10µA max over temperature. Pulling PSHDN low turns off the positive linear regula­tor; the doubler charge pump remains active. Pulling the NSHDN input low while PSHDN remains high turns off the inverter charge pump, the negative linear regula­tor, and the output-ready indicator (Table 1).
Capacitors
The overall dropout voltage is a function of the charge pump’s output resistance and the voltage drop across the linear regulator. The charge-pump output resistance is a function of the switching frequency and the capaci­tor’s ESR value. Therefore, minimizing the charge-pump capacitors’ ESR minimizes dropout voltage.
R 84 8 C1 C3
=+
POUT ESR ESR
R 84 8 C1 4 C2
=+
NOUT ESR ESR
(C4 )
() ()
ESR
+
()
+
()
2
++
fC1
OSC OSC
fC2
+
fC1
OSC
+
1
2
CAPACITORS
V
IN
C2
C4
10µF
C1­GND
C2-
V­NOUT SETN
NSHDN
PSHDN
MAX768
C2+
C1+
POUT
SETP
RDY
SYNC
4.7µF
C1
IN
C3
V+
C7
+5V
C5
TO V
IN
C6
-5V
See Table 2 for capacitor selection. All capacitors
SEE TABLE 2 FOR CAPACITOR VALUES
should be either surface-mount ceramic chip or tanta­lum. External capacitor values may be adjusted to opti­mize size, performance, and cost.
8 _______________________________________________________________________________________
Figure 2. MAX768 Standard Application Circuit
Low-Noise, Dual-Output, Regulated Charge Pump
for GaAsFET, LCD, and VCO Supplies
R2
= (1.25) (1+ )
V
V
IN
C1
C2
Figure 3. MAX768 Adjustable Configuration
IN SYNC
C1+
C1­C2+
C2-
NSHDN
PSHDN
POUT
SETP
MAX768
GND
SETN
NOUT
RDY
POUT
R2
V
R1
R3
R4
NOUT
V+
V-
Switching-Frequency Control
For applications sensitive to the MAX768’s internal switching frequency, connect an external TTL/CMOS (within IN and GND) clock to SYNC. The clock must be a 20kHz to 240kHz square wave between 40% and 60% duty cycle.
Schottky Diodes
When under heavy loads, where POUT is sourcing into NOUT (i.e., load current flows from POUT to NOUT, rather than from supply to ground), do not allow NOUT to pull above ground. In applications where large cur­rents from POUT to NOUT are likely, use a Schottky diode (1N5817) between GND and NOUT, with the anode connected to GND (Figure 4).
Connect a IN5817-type Schottky diode from C2- to V­to assure proper start-up.
C3
C4
= (-1.25) (1 + )
R1
GND
C5
C6
R4 R3
Figure 4. A Schottky diode protects the MAX768 when a large current flows from POUT to NOUT.
MAX768
NOUT
Layout and Grounding
Good layout is important, primarily for good noise per­formance:
1) Mount all components as close together as possi­ble.
2) Keep traces short to minimize parasitic inductance and capacitance. This includes connections to SETP and SETN.
3) Use a ground plane.
Noise and Ripple Measurement
Accurately measuring output noise and ripple can be difficult. Brief differences in ground potential between the circuit and the oscilloscope (which result from the charge pump’s switching action) cause ground cur­rents in the probe’s wires, inducing sharp voltage spikes. For best results, measure directly across output capacitor C3, C4, C5, or C6. Do not use the oscillo­scope probe’s ground lead; instead, remove the cover’s ground lead and touch the ground ring on the probe directly to the ground terminal of C3, C4, C5, or C6. Or, use a Tektronix chassis-mount test jack (part no. 131-0258) to connect your scope probe directly. This direct connection provides the most accurate noise and ripple measurement.
MAX768
_______________________________________________________________________________________ 9
Low-Noise, Dual-Output, Regulated Charge Pump for GaAsFET, LCD, and VCO Supplies
__________________Pin Configuration
TOP VIEW
16
C2+ IN
15 14
C1+
13
V+
12
POUT
11
SETP
10
RDY
9
SYNC
MAX768
NSHDN
PSHDN
C1-
GND
C2-
NOUT
SETN
1 2 3 4
MAX768
V-
5 6 7 8
QSOP
___________________Chip Information
TRANSISTOR COUNT: 657 SUBSTRATE CONNECTED TO GND
10 ______________________________________________________________________________________
Low-Noise, Dual-Output, Regulated Charge Pump
for GaAsFET, LCD, and VCO Supplies
________________________________________________________Package Information
INCHES MILLIMETERS
DIM
D
A
e
A1
B
S
H
E
A A1 A2
B
C
D
E
e
H
h
L N S
α
MAX
MIN
0.061
0.0098
0.004
0.055
0.008
0.0098
0.0075 SEE PIN COUNT VARIATIONS
0.150
0.230
0.010
0.016 SEE PIN COUNT VARIATIONS SEE PIN COUNT VARIATIONS
0.068
0.061
0.012
0.157
0.244
0.016
0.035
MIN
1.55
0.127
1.40
0.20
0.19
3.81
0.635 BSC0.25 BSC
5.84
0.25
0.41
MAX
1.73
0.25
1.55
0.31
0.25
3.99
6.20
0.41
0.89
DIM
D S D S D S D S
h x 45°
N
A2
α
SMALL-OUTLINE
E
C
L
INCHES MILLIMETERS
PINS
MIN
0.189
0.0020
0.337
0.0500
0.337
0.0250
0.386
0.0250
MAX
0.196
0.0070
0.344
0.0550
0.344
0.0300
0.393
0.0300
16 16 20 20 24 24 28 28
QSOP
QUARTER
PACKAGE
MIN
4.80
0.05
8.56
1.27
8.56
0.64
9.80
0.64
MAX
4.98
0.18
8.74
1.40
8.74
0.76
9.98
0.76
21-0055A
MAX768
______________________________________________________________________________________ 11
Low-Noise, Dual-Output, Regulated Charge Pump for GaAsFET, LCD, and VCO Supplies
NOTES
MAX768
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
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.
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
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
12
__________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600
12
__________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600
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.
© 1996 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
© 1996 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
© 1996 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
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