MAX1853EXT-T Fast Delivery |IC PHOENIX CO.,LIMITED

MAX1853EXT-T ,SC70 Inverting Charge Pumps with ShutdownApplicationsNegative Supply from +5V or +3.3V Logic SuppliesSmall LCD PanelsOrdering InformationGaA ..
MAX1854EEG ,High-Speed / Adjustable / Synchronous Step-Down Controllers with Integrated Voltage PositioningApplicationsV VCC DDV+SHDNNotebook ComputersILIM BSTDocking StationsDHREFOUTPUTCPU Core SupplyMAX17 ..
MAX1856EUB ,Wide Input Range / Synchronizable / PWM SLIC Power SupplyFeaturesThe MAX1856 offers a low-cost solution for generating a Low-Cost, Off-the-Shelf Transforme ..
MAX1856EUB+ ,Wide-Input-Range, Synchronizable, PWM SLIC Power SupplyELECTRICAL CHARACTERISTICS(V = SYNC/SHDN, V = 5V, V = 5V, R = 200kΩ, T = 0°C to +85°C. Typical valu ..
MAX1856EUB+T ,Wide-Input-Range, Synchronizable, PWM SLIC Power SupplyFeaturesThe MAX1856 offers a low-cost solution for generating a♦ Low-Cost, Off-the-Shelf Transforme ..
MAX1857EUA47 ,500mA / Low-Dropout / Ripple-Rejecting LDO in MAXELECTRICAL CHARACTERISTICS(V = +5.25V, V = 4.75V, SHDN = IN, SET = GND, T = 0°C to +85°C, unless ot ..
MAX4762ETB ,Low-Voltage / Dual SPDT / Audio Clickless Switches with Negative Rail CapabilityELECTRICAL CHARACTERISTICS(V = +2.7V to +5.5V, T = -40°C to +85°C, unless otherwise noted. Typical ..
MAX4762ETB+ ,Low-Voltage, Dual SPDT, Audio Clickless Switches with Negative Rail CapabilityMAX4762–MAX4764/MAX4764A/MAX476519-3152; Rev 2; 1/06Low-Voltage, Dual SPDT, Audio ClicklessSwitches ..
MAX4762ETB+T ,Low-Voltage, Dual SPDT, Audio Clickless Switches with Negative Rail CapabilityELECTRICAL CHARACTERISTICS(V = +2.7V to +5.5V, T = -40°C to +85°C, unless otherwise noted. Typical ..
MAX4762EUB+ ,Low-Voltage, Dual SPDT, Audio Clickless Switches with Negative Rail CapabilityELECTRICAL CHARACTERISTICS(V = +2.7V to +5.5V, T = -40°C to +85°C, unless otherwise noted. Typical ..
MAX4764AETB+T ,Low-Voltage, Dual SPDT, Audio Clickless Switches with Negative Rail CapabilityELECTRICAL CHARACTERISTICS(V = +2.7V to +5.5V, T = -40°C to +85°C, unless otherwise noted. Typical ..
MAX4764EBC ,Low-Voltage, Dual SPDT, Audio Clickless Switches with Negative Rail CapabilityELECTRICAL CHARACTERISTICS(V = +2.7V to +5.5V, T = -40°C to +85°C, unless otherwise noted. Typical ..

MAX1853EXT-T
SC70 Inverting Charge Pumps with Shutdown
General Description
The MAX1852/MAX1853 monolithic, CMOS charge-
pump voltage inverters in the ultra-small SC70 package
feature a low 15Ωoutput resistance, permitting loads
up to 30mA with maximum efficiency. The MAX1852/
MAX1853 are available with operating frequencies of
50kHz and 200kHz, respectively, allowing optimization
of supply current or external component size. Small
external components and micropower shutdown mode
make these devices ideal for both battery-powered and
board-level voltage conversion applications.
Oscillator control circuitry and four power-MOSFET
switches are included on-chip. Applications include
generating a negative supply from a +5V or +3.3V logic
supply to power analog circuitry. Both versions come in
a 6-pin SC70 package that is 40% smaller than a
SOT23.
Applications
Negative Supply from +5V or +3.3V Logic Supplies
Small LCD Panels
GaAsFET Bias Supplies
Handy-Terminals, PDAs
Battery-Operated Equipment
Features30mA Output Current Low 15ΩOutput Resistance68µA Supply Current (MAX1852)Requires Only Two 0.68µF Capacitors (MAX1853)+2.5V to +5.5V Input Voltage Range0.1µA Logic-Controlled ShutdownTwo Switching Frequencies
50kHz (MAX1852)
200kHz (MAX1853)Slew-Rate Limited to Reduce EMIUltra-Small 6-Pin SC70 Package
MAX1852/MAX1853
SC70 Inverting Charge Pumps
with Shutdown
TOP VIEW
GNDC1-
C1+OUT
SC70-66
MAX1852
MAX185324SHDN
Pin Configuration
C1+C1-
SHDN
OUT
GND
0.68μF
0.68μF
OFF
INPUT
2.5V TO 5.5V
NEGATIVE
OUTPUT
-1 ✕ VIN
30mA
MAX1853ypical Operating Circuit
19-1792; Rev 0; 9/00
Ordering Information
PARTTEMP.
RANGE
PIN -
PA C K A G E
TOP
MARK
MAX1852EXT- 40°C to + 85°C 6 SC70AAL
MAX1853EXT- 40°C to + 85°C 6 SC70AAM
MAX1852/MAX1853
SC70 Inverting Charge Pumps
with Shutdown
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, capacitors from Table 2, VIN= +5V, SHDN= IN, TA= -40°C to +85°C, unless otherwise noted. Typical values are
at TA= +25°C.) (Note 1)
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.
IN to GND.................................................................-0.3V to +6V
C1+, SHDNto GND.....................................-0.3V to (VIN + 0.3V)
C1- to GND...............................................(VOUT- 0.3V) to +0.3V
OUT to GND.............................................................+0.3V to -6V
OUT Short-Circuit to GND..............................................1 minute
Continuous Power Dissipation (TA= +70°C)
6-Pin SC70 (derate 3.1mW/°C above +70°C) .............245mW
Operating Temperature Range...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Note 1:All devices are 100% production tested at TA = +25°C. All temperature limits are guaranteed by design.
Note 2:Output resistance is guaranteed with capacitor ESR of 0.3Ωor less.
PARAMETERCONDITIONSMINTYPMAXUNITS
Supply Voltage Range2.55.5V
TA = +25°C75130MAX1852TA = -40°C to +85°C150
TA = +25°C165320Quiescent Supply Current
MAX1853TA = -40°C to +85°C350
TA = +25°C0.0020.5Shutdown Supply CurrentSHDN = GNDTA = +85°C0.01µA
TA = +25°C325068MAX1852TA = -40°C to +85°C2578
TA = +25°C130200270Oscillator Frequency
MAX1853TA = -40°C to +85°C110310
kHz
Voltage Conversion EfficiencyIOUT = 09999.9%
TA = +25°C1530Output Resistance (Note 2)IOUT = 10mATA = -40°C to +85°C40Ω
Output CurrentContinuous, long-term30mARMS
SHDN Input Logic High+2.5V ≤ VIN ≤ +5.5V0.7 × VINV
SHDN Input Logic Low+2.5V ≤ VIN ≤ +5.5V0.3 × VINV
TA = +25°C-1001100SHDN Bias CurrentSHDN = GND or INTA = +85°C10nA
MAX1852260Wake-Up Time From ShutdownIOUT = 5mAMAX1853112µs
MAX1852/MAX1853
SC70 Inverting Charge Pumps
with Shutdown
MAX1853
OUTPUT RESISTANCE vs. TEMPERATURE
MAX1852/3 toc09
TEMPERATURE (°C)
OUTPUT RESISTANCE (
VIN = +3.3V
VIN = +5V
VIN = +2.5V
MAX1852
OUTPUT RESISTANCE vs. TEMPERATURE
MAX1852/3 toc08
TEMPERATURE (°C)
OUTPUT RESISTANCE (
VIN = +2.5V
VIN = +5V
VIN = +3.3V
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX1852/3 toc07
TEMPERATURE (°C)
SUPPLY CURRENT (nA)
MAX1852
OUTPUT VOLTAGE
vs. LOAD CURRENT
MAX1852/3 toc01
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
VIN = +3.3V
VIN = +5V
MAX1853
EFFICIENCY vs. LOAD CURRENT
MAX1852/3 toc04
LOAD CURRENT (mA)
EFFICIENCY (%)
VIN = +3.3V
VIN = +2.5V
VIN = +5V
MAX1853
OUTPUT VOLTAGE
vs. LOAD CURRENT
MAX1852/3 toc02
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
VIN = +3.3V
VIN = +5V
MAX1852
EFFICIENCY vs. LOAD CURRENT
MAX1852/3 toc03
LOAD CURRENT (mA)
EFFICIENCY (%)
VIN = +5V
VIN = +2.5V
VIN = +3.3V
OUTPUT RESISTANCE vs. INPUT VOLTAGE
MAX1852/3 toc05
INPUT VOLTAGE (V)
OUTPUT RESISTANCE (
MAX1852
MAX1853
NO-LOAD SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX1852/3 toc06
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (
MAX1853
MAX1852
Typical Operating Characteristics
(Circuit of Figure 1, capacitors from Table 2, VIN= +5V, SHDN= IN, TA= +25°C, unless otherwise noted.)
MAX1852/MAX1853
SC70 Inverting Charge Pumps
with Shutdown
MAX1852
CHARGE-PUMP FREQUENCY
vs. TEMPERATURE
MAX1852/3 toc10
TEMPERATURE (°C)
FREQUENCY (kHz)
MAX1853
CHARGE-PUMP FREQUENCY
vs. TEMPERATURE
MAX1852/3 toc11
TEMPERATURE (°C)
FREQUENCY (kHz)
CHARGE-PUMP FREQUENCY
vs. INPUT VOLTAGE
MAX1852/3 toc12
INPUT VOLTAGE (V)
FREQUENCY (kHz)
MAX1853
MAX1852
MAX1852 AND MAX1853
OUTPUT VOLTAGE vs. INPUT VOLTAGE
MAX1852/3 toc13
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
ILOAD = 10mA
2μs/div
ILOAD = 10mA, AC-COUPLED
MAX1853
OUTPUT NOISE AND RIPPLE
MAX1852/3 toc16
VOUT
20mV/div
C1 = C2 = 1μF
OUTPUT VOLTAGE RIPPLE
vs. CAPACITANCE
MAX1852/3 toc14
CAPACITANCE (μF)
OUTPUT VOLTAGE RIPPLE (mV)MAX1853
C1 = C2
ILOAD = 10mA
MAX1852
10μs/div
ILOAD = 10mA, AC-COUPLED
MAX1852
OUTPUT NOISE AND RIPPLE
MAX1852/3 toc15
VOUT
20mV/div
C1 = C2 = 4.7μF
100μs/div
MAX1852
STARTUP FROM SHUTDOWN
MAX1852/3 toc17
SHDN
VOUT
2V/div
40μs/div
MAX1853
STARTUP FROM SHUTDOWN
MAX1852/3 toc18
SHDN
VOUT
2V/divypical Operating Characteristics (continued)
(Circuit of Figure 1, capacitors from Table 2, VIN= +5V, SHDN= IN, TA= +25°C, unless otherwise noted.)
Detailed Description
The MAX1852/MAX1853 charge pumps invert the volt-
age applied to their input. For highest performance use
low equivalent series resistance (ESR) capacitors (e.g.,
ceramic).
During the first half-cycle, switches S2 and S4 open,
switches S1 and S3 close, and capacitor C1 charges to
the voltage at IN (Figure 2). During the second half-
cycle, S1 and S3 open, S2 and S4 close, and C1 is level
shifted downward by VINvolts. This connects C1 in par-
allel with the reservoir capacitor C2. If the voltage across
C2 is smaller than the voltage across C1, charge flows
from C1 to C2 until the voltage across C2 reaches
-VIN. The actual voltage at the output is more positive
than -VINsince switches S1–S4 have resistance and the
load drains charge from C2.
Efficiency Considerations
The efficiency of the MAX1852/MAX1853is dominated
by their quiescent supply current (IQ) at low output cur-
rent and by their output impedance (ROUT) at higher
output current; it is given by:
where the output impedance is roughly approximated
by:
The first term is the effective resistance of an ideal
switched-capacitor circuit (Figures 3a and 3b), and
RSWis the sum of the charge pump’s internal switch
resistances (typically 6Ωat VIN= +5V). The typical out-
put impedance is more accurately determined from the
Typical Operating Characteristics.
Shutdown
The MAX1852/MAX1853have a logic-controlled shut-
down input. Driving SHDNlow places the devices in a
low-power shutdown mode. The charge-pump switch-
ing halts, supply current is reduced to 2nA.
Driving SHDNhigh will restart the charge pump. The
switching frequency and capacitor values determine how
soon the device will reach 90% of the input voltage.
Applications Information
Capacitor Selection
The charge-pump output resistance is a function of the
ESR of C1 and C2. To maintain the lowest output resis-
tance, use capacitors with low ESR. (See Table 1 for a
list of recommended manufacturers.) Tables 2 and 3
suggest capacitor values for minimizing output resis-
tance or capacitor size.
Flying Capacitor (C1)
Increasing the flying capacitor’s value reduces the out-
put resistance. Above a certain point, increasing C1’s
capacitance has negligible effect because the output
resistance is then dominated by internal switch resis-
tance and capacitor ESR.
Output Capacitor (C2)
Increasing the output capacitor’s value reduces the
output ripple voltage. Decreasing its ESR reduces both
output resistance and ripple. Lower capacitance values
can be used with light loads if higher output ripple can
be tolerated. Use the following equation to calculate the
peak-to-peak ripple:1 x C14ESRESROUT
OSCC1C2≅()+II x R
OUT
OUTQ
OUTOUT+−
MAX1852/MAX1853
SC70 Inverting Charge Pumps
with Shutdown
Pin DescriptionPositive Terminal of the Flying
CapacitorInverting Charge-Pump OutputGround
Shutdown Input. Drive this pin high
for normal operation; drive it low for
shutdown mode.Power-Supply Voltage Input. Input
range is +2.5V to +5.5V.Negative Terminal of the Flying
Capacitor
PINFUNCTIONNAME
C1+
OUT
GND
SHDN
C1-
TE: ( ON
OFF
C1+C1-
SHDN
OUT
GND
INPUT
2.5V TO 5.5VNEGATIVE
OUTPUT
-1 ✕ VIN
MAX1852
MAX1853
Figure 1. Typical Application Circuit
MAX1852/MAX1853
SC70 Inverting Charge Pumps
with Shutdown
Input Bypass Capacitor (C3)
If necessary, bypass the incoming supply to reduce its
AC impedance and the impact of the MAX1852/
MAX1853s’ switching noise. A bypass capacitor with a
value equal to that of C1 is recommended.
Voltage Inverter
The most common application for these devices is a
charge-pump voltage inverter (Figure 1). This applica-
tion requires only two external components—capacitors
C1 and C2—plus a bypass capacitor, if necessary.
Refer to the Capacitor Selection section for suggested
capacitor types.
Cascading Devices
Two devices can be cascaded to produce an even
larger negative voltage (Figure 4). The unloaded output
voltage is normally -2 ✕VIN, but this is reduced slightly
by the output resistance of the first device multiplied by
the quiescent current of the second. When cascading
more than two devices, the output resistance rises sig-
nificantly. For applications requiring larger negative
voltages, see the MAX865 and MAX868 data sheets.
Paralleling Devices
Paralleling multiple MAX1852/MAX1853s reduces the
output resistance. Each device requires its own pump
capacitor (C1), but the reservoir capacitor (C2) serves
all devices (Figure 5). Increase C2’s value by a factor of
n, where nis the number of parallel devices. Figure 5
shows the equation for calculating output resistance.
Combined Doubler/Inverter
In the circuit of Figure 6, capacitors C1 and C2 form the
inverter, while C3 and C4 form the doubler. C1 and C3
are the pump capacitors; C2 and C4 are the reservoir
capacitors. Because both the inverter and doubler use
part of the charge-pump circuit, loading either output
causes both outputs to decline toward GND. Make sure
the sum of the currents drawn from the two outputs
does not exceed 30mA.
Heavy Load Connected to a
Positive Supply
Under heavy loads, where a higher supply is sourcing
current into OUT, the OUT supply must not be pulled
above ground. Applications that sink heavy current into
OUT require a Schottky diode (1N5817) between GND
and OUT, with the anode connected to OUT (Figure 7).
Layout and Grounding
Good layout is important, primarily for good noise per-
formance. To ensure good layout, mount all compo-
nents as close together as possible, keep traces short
to minimize parasitic inductance and capacitance, and
use a ground plane.I
2(f)C22IESRRIPPLEOUT
OSC
OUTC2+××S4
VOUT = -(VIN)
Figure 2. Ideal Voltage Inverter
fOSCRL
VOUT
Figure 3a. Switched-Capacitor Model
REQUIV =
REQUIV
VOUT
fOSC ✕ C1C2
Figure 3b. Equivalent Circuit

Partno	Mfg	Dc	Qty	Available	Descript
MAX1853EXT-T \|MAX1853EXTT	MAXIM	N/a	1	avai	SC70 Inverting Charge Pumps with Shutdown