MAX1721EUT+T ,SOT23, Switched-Capacitor Voltage Inverters with Shutdownapplications.♦ ♦ 25mA Output CurrentOscillator control circuitry and four power MOSFET♦ ♦ Requires ..
MAX1721EUT-T ,SOT23, Switched-Capacitor Voltage Inverters with ShutdownApplicationsMAX1721EUT -40°C to +85°C 6 SOT23-6 AABTLocal Negative Supply from a Positive SupplySma ..
MAX1722EZK+T ,1.5µA IQ, Step-Up DC-DC Converters in TSOT and µDFNElectrical Characteristics(V = 1.2V, V = 3.3V (MAX1722/MAX1723), V = V (MAX1724), SHDN = OUT, R = ∞ ..
MAX1722EZK-T ,1.5uA IQ / Step-Up DC-DC Converters in Thin SOT23-5ELECTRICAL CHARACTERISTICS (continued)(V = 1.2V, V = 3.3V (MAX1722/MAX1723), V = V (MAX1724), SHDN ..
MAX1722EZK-T ,1.5uA IQ / Step-Up DC-DC Converters in Thin SOT23-5MAX1722/MAX1723/MAX172419-1735; Rev 0; 7/011.5µA I , Step-Up DC-DC ConvertersQin Thin SOT23-5
MAX1723EZK+T ,1.5µA IQ, Step-Up DC-DC Converters in TSOT and µDFNFeaturesThe MAX1722/MAX1723/MAX1724 compact, high-efficiency, ● Up to 90% Efficiencystep-up DC-DC c ..
MAX4551CPE ,15kV ESD-Protected / Quad / Low-Voltage / SPST Analog SwitchesELECTRICAL CHARACTERISTICS—Dual Supplies(V+ = +5V, ±10%, V- = -5V, ±10%, T = T to T , unless otherw ..
MAX4551CSE ,15kV ESD-Protected / Quad / Low-Voltage / SPST Analog SwitchesGeneral Description ________
MAX4551EPE ,15kV ESD-Protected / Quad / Low-Voltage / SPST Analog SwitchesApplications MAX4551CSE 0°C to +70°C 16 Narrow SOMAX4551CPE 0°C to +70°C 16 Plastic DIPBattery-Oper ..
MAX4551ESE ,15kV ESD-Protected / Quad / Low-Voltage / SPST Analog SwitchesApplications MAX4551CSE 0°C to +70°C 16 Narrow SOMAX4551CPE 0°C to +70°C 16 Plastic DIPBattery-Oper ..
MAX4551ESE+ ,±15kV ESD-Protected, Quad, Low-Voltage, SPST Analog SwitchesApplications MAX4551CSE 0°C to +70°C 16 Narrow SOMAX4551CPE 0°C to +70°C 16 Plastic DIPBattery-Oper ..
MAX4552CEE+ ,±15kV ESD-Protected, Quad, Low-Voltage, SPST Analog SwitchesFeaturesThe MAX4551/MAX4552/MAX4553 are quad, low-volt-♦ ±15kV ESD Protection per IEC 1000-4-2age, ..
MAX1719EUT+T-MAX1720EUT+-MAX1720EUT+T-MAX1721EUT+T-MAX1721EUT-T
SOT23, Switched-Capacitor Voltage Inverters with Shutdown
General DescriptionThe ultra-small MAX1719/MAX1720/MAX1721 monolithic,
CMOS charge-pump inverters accept input voltages
ranging from +1.5V to +5.5V. The MAX1720 operates at
12kHz, and the MAX1719/MAX1721 operate at 125kHz.
High efficiency, small external components, and logic-
controlled shutdown 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. A typical MAX1719/
MAX1720/MAX1721 application is generating a -5V
supply from a +5V logic supply to power analog circuitry.
All three parts come in a 6-pin SOT23 package and can
deliver a continuous 25mA output current.
For pin-compatible SOT23 switched-capacitor voltage
inverters without shutdown (5-pin SOT23), see the
MAX828/MAX829 and MAX870/MAX871 data sheets. For
applications requiring more power, the MAX860/MAX861
deliver up to 50mA. For regulated outputs (up to -2 x VIN),
refer to the MAX868. The MAX860/MAX861 and MAX868
are available in space-saving µMAX packages.
ApplicationsLocal Negative Supply from a Positive Supply
Small LCD Panels
GaAs PA Bias Supply
Handy-Terminals, PDAs
Battery-Operated Equipment
Features♦
1nA Logic-Controlled Shutdown♦
6-Pin SOT23 Package♦
99.9% Voltage Conversion Efficiency♦
50µA Quiescent Current (MAX1720)♦
+1.5V to +5.5V Input Voltage Range♦
25mA Output Current♦
Requires Only Two 1µF Capacitors
(MAX1719/MAX1721)
MAX1719/MAX1720/MAX1721
SOT23, Switched-Capacitor
Voltage Inverters with ShutdownTOP VIEW
GNDC1-
C1+OUT
( ) ARE FOR MAX1719
SOT23-66
SHDN (SHDN)MAX1719
MAX1720
MAX17214
Pin ConfigurationC1+C1-
SHDN
OUT
GND
1μF
1μF
OFF
INPUT
1.5V to 5.5V
NEGATIVE
OUTPUT
-1 ·VIN
25mA
MAX1721
Typical Operating Circuit19-1439; Rev 2; 4/04
PART
MAX1719EUT-40°C to +85°C
TEMP RANGEPIN-
PACKAGE6 SOT23-6
Ordering Information
SOT
TOP MARKAACA
MAX1721EUT-40°C to +85°C6 SOT23-6AABT
MAX1720EUT-40°C to +85°C6 SOT23-6AABS
MAX1719/MAX1720/MAX1721
SOT23, Switched-Capacitor
Voltage Inverters with Shutdown
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VIN= +5V, SHDN = GND (MAX1719), SHDN= IN (MAX1720/MAX1721), C1 = C2 = 10µF (MAX1720), C1 = C2 = 1µF
(MAX1719/MAX1721), circuit of Figure 1, TA
= 0°C to +85°C, 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.
IN to GND.................................................................-0.3V to +6V
OUT to GND.............................................................-6V to +0.3V
C1+, SHDN,SHDN to GND.........................-0.3V to (VIN+ 0.3V)
C1- to GND...............................................(VOUT- 0.3V) to +0.3V
OUT Output Current..........................................................100mA
OUT Short Circuit to GND..............................................Indefinite
Continuous Power Dissipation (TA= +70°C)
6-Pin SOT23 (derate 8.7mW/°C above +70°C).................696mW
Operating Temperature Range...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
IOUT= 5mA
MAX1719/MAX1721= 10kΩ
SHDN/SHDN= GND
or VIN
VIN(MIN)≤VIN≤+2.5V
MAX1720= 10kΩ
+2.5V ≤VIN≤+5.5V
VIN(MIN)≤VIN≤+2.5V
+2.5V ≤VIN≤+5.5V
IOUT= 0, TA= +25°C
SHDN = IN (MAX1719),SHDN= GND
(MAX1720/MAX1721), OUT is internally
forced to GND in shutdown= +25°C= +25°C
SHDN = IN (MAX1719),
SHDN= GND
(MAX1720/MAX1721)
IOUT= 10mA
CONDITIONSµs800Wake-Up Time from ShutdownnA-1000.05100IIL, IIHSHDN/SHDNBias Current
0.2V0.6VILSHDN/SHDNInput Logic Low
VIN- 0.2V2.0VIHSHDN/SHDNInput Logic High412RO, SHDNOUT to GND
Shutdown ResistanceΩ2350ROOutput Resistance (Note 1)
1.55.5V
VINSupply Voltage Range9999.9Voltage Conversion Efficiency125180kHz71217fOSCOscillator Frequency
1.55.55090ICCQuiescent Supply Current
(Note 3)350650
ISHDNShutdown Supply Current
UNITSMINTYPMAXSYMBOLPARAMETER= 0°C to + 85°C= +25°C= 0°C to + 85°C= +25°C
MAX1719/MAX1721
MAX1720= +85°C= +25°C
MAX1719/MAX1721
MAX1720= 0°C to +85°C= +25°C= +85°C= +25°C
MAX1719/MAX1721
MAX1720
MAX1719/MAX1720/MAX1721
SOT23, Switched-Capacitor
Voltage Inverters with ShutdownOUTPUT VOLTAGE
vs. OUTPUT CURRENT
MAX1720/21toc01
OUTPUT CURRENT (mA)
OUTPUT VOLTAGE (V)
VIN = +1.5VVIN = +2V
VIN = +3.3V
VIN = +5V
MAX1720
EFFICIENCY vs. OUTPUT CURRENT
MAX1720/21toc02
OUTPUT CURRENT (mA)
EFFICIENCY (%)
VIN = +1.5VVIN = +3.3VVIN = +2V
VIN = +5V
MAX1719/MAX1721
EFFICIENCY vs. OUTPUT CURRENT
MAX1720/21toc03
OUTPUT CURRENT (mA)
EFFICIENCY (%)
VIN = +1.5V
VIN = +2V
VIN = +3.3V
VIN = +5V
Typical Operating Characteristics(Circuit of Figure 1, VIN= +5V, SHDN = GND (MAX1719), SHDN= IN (MAX1720/MAX1721), C1 = C2 = C3, TA= +25°C, unless other-
wise noted.)
ELECTRICAL CHARACTERISTICS(VIN= +5V, SHDN = GND (MAX1719), SHDN= IN (MAX1720/MAX1721), C1 = C2 = 10µF (MAX1720), C1 = C2 = 1µF
(MAX1719/MAX1721), circuit of Figure 1, TA
= -40°C to +85°C, unless otherwise noted.) (Note 2)VIN(MIN)≤VIN≤+2.5V= 10kΩ
+2.5V ≤VIN≤+5.5V
VIN(MIN)≤VIN≤+2.5V
+2.5V ≤VIN≤+5.5V
IOUT= 0
SHDN = IN (MAX1719),SHDN= GND
(MAX1720/MAX1721), OUT is internally
forced to GND in shutdown
MAX1720
IOUT= 10mA
CONDITIONS0.2V0.6VILSHDN/SHDNInput Logic Low
VIN- 0.2V2.1VIHSHDN/SHDNInput Logic High12RO, SHDNOUT to GND Shutdown
ResistanceΩROOutput Resistance (Note 1)
MAX1719/MAX1721
1.65.5MAX1719/MAX1721
1.55.5MAX172099Voltage Conversion Efficiency200kHz621fOSCOscillator Frequency100ICCQuiescent Current (Note 3)750
UNITSMINTYPMAXSYMBOLPARAMETERVINSupply Voltage Range
MAX1720
Note 1:Capacitor contribution (ESR component plus (1/fOSC) ·C) is approximately 20% of output impedance.
Note 2:All specifications from -40°C to +85°C are guaranteed by design, not production tested.
Note 3:The MAX1719/MAX1720/MAX1721 may draw high supply current during startup, up to the minimum operating supply voltage.
To guarantee proper startup, the input supply must be capable of delivering 90mA more than the maximum load current.
Continuous, long-term25mARMSIOUTOutput Current
MAX1719/MAX1721
MAX1720
OUTPUT VOLTAGE RIPPLE
vs. CAPACITANCE
MAX1720/21toc12
CAPACITANCE (μF)
OUTPUT VOLTAGE RIPPLE (mVp-p)
VIN = +4.75V, VOUT = -4.0V
VIN = +3.15V, VOUT = -2.5V
VIN = +1.9V, VOUT = -1.5V
MAX1720
OUTPUT CURRENT vs. CAPACITANCE
MAX1720/21toc11
CAPACITANCE (μF)
OUTPUT CURRENT (mA)VIN = +1.9V, VOUT = -1.5V
VIN = +3.15V, VOUT = -2.5V
VIN = +4.75V, VOUT = -4.0V
MAX1719/MAX1720/MAX1721
SOT23, Switched-Capacitor
Voltage Inverters with Shutdown500μs/div
MAX1720
START-UP FROM SHUTDOWNRL = 1kΩ
VOUT
2V/div
MAX1720/21toc10
VSHDN
5V/div
OUTPUT RESISTANCE
vs. INPUT VOLTAGE
MAX1720/21toc04
INPUT VOLTAGE (V)
OUTPUT RESISTANCE (
MAX1720
MAX1719/
MAX1721
OUTPUT RESISTANCE
vs. TEMPERATURE
MAX1720/21toc07
TEMPERATURE (°C)
OUTPUT RESISTANCE (
VIN = +2V
VIN = +1.5V
VIN = +3.3V
VIN = +5V
SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX1720/21toc05
INPUT VOLTAGE (V)
SUPPLY CURRENT (
MAX1720
MAX1719/
MAX1721
+85°C
+85°C
-40°C
-40°C
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX1720/21toc06
TEMPERATURE (°C)
SHUTDOWN SUPPLY CURRENT (nA)
VIN = +5V
VIN = +3.3V
VIN = +1.5V
PUMP FREQUENCY
vs. TEMPERATURE
MAX1720/21toc08
TEMPERATURE (°C)
FREQUENCY (kHz)
MAX1719/MAX1721
VIN = +5V
VIN = +1.5VMAX1720
VIN = +1.5V
VIN = +5V
10μs/div
OUTPUT NOISE AND RIPPLEVIN = 3.3V, VOUT = -3.17V, IOUT = 5mA
20mV/div, AC-COUPLED
VOUT
MAX1719/
MAX1721
VOUT
MAX1720
MAX1720/21toc09
Typical Operating Characteristics (continued)(Circuit of Figure 1, VIN= +5V, SHDN = GND (MAX1719), SHDN= IN (MAX1720/MAX1721), C1 = C2 = C3, TA= +25°C, unless oth-
erwise noted.)
Detailed DescriptionThe MAX1719/MAX1720/MAX1721 capacitive charge
pumps invert the voltage applied to their input. For high-
est 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 -VIN, since switches S1–S4 have resistance and the
load drains charge from C2.
MAX1719/MAX1720/MAX1721
SOT23, Switched-Capacitor
Voltage Inverters with Shutdown
Typical Operating Characteristics (continued)(Circuit of Figure 1, VIN= +5V, SHDN = GND (MAX1719), SHDN= IN (MAX1720/MAX1721), C1 = C2 = C3, TA= +25°C, unless
otherwise noted.)
MAX1719/MAX1721
OUTPUT VOLTAGE RIPPLE vs. CAPACITANCE
MAX1720/21toc15
CAPACITANCE (μF)
OUTPUT VOLTAGE RIPPLE (mVp-p)
VIN = +4.75V, VOUT = -4.0V
VIN = +3.15V, VOUT = -2.5V
VIN = +1.9V, VOUT = -1.5V
50μs/div
MAX1721
START-UP FROM SHUTDOWNRL = 1kΩ
VOUT
2V/div
MAX1720/21toc13
VSHDN
5V/div
Noninverting Shutdown Input. Drive this pin low for normal operation; drive it high for
shutdown mode. OUT is actively pulled to ground during shutdown.SHDN5
GroundGND4
Negative Terminal of Flying CapacitorC1-3
Power-Supply Positive Voltage InputIN2
Inverting Charge-Pump OutputOUT1
FUNCTIONNAME
MAX1719/MAX1721
OUTPUT CURRENT vs. CAPACITANCEMAX1720/21toc14
CAPACITANCE (μF)
OUTPUT CURRENT (mA)
VIN = +1.9V, VOUT = -1.5V
VIN = +4.75V, VOUT = -4.0V
VIN = +3.15V, VOUT = -2.5V
Positive Terminal of Flying CapacitorC1+6
Pin DescriptionInverting Shutdown Input. Drive this pin high for normal operation; drive it low for
shutdown mode. OUT is actively pulled to ground during shutdown.SHDN–5
MAX1720
MAX1721MAX1719
PIN
MAX1719/MAX1720/MAX1721
SOT23, Switched-Capacitor
Voltage Inverters with Shutdown
Charge-Pump OutputThe MAX1719/MAX1720/MAX1721 are not voltage reg-
ulators: the charge pumps’ output resistance is
approximately 23Ωat room temperature (with VIN=
+5V), and VOUTapproaches -5V when lightly loaded.
VOUTwill droop toward GND as load current increases.
The droop of the negative supply (VDROOP-) equals the
current draw from OUT (IOUT) times the negative con-
verter’s output resistance (RO):
VDROOP-= IOUTx RO
The negative output voltage will be:
VOUT= -(VIN- VDROOP-)
Efficiency ConsiderationsThe efficiency of the MAX1719/MAX1720/MAX1721 is
dominated by its quiescent supply current (IQ) at low
output current and by its 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 8Ωto 9Ωat VIN= +5V). The typi-
cal output impedance is more accurately determined
from the Typical Operating Characteristics.
Shutdown ModeThe MAX1719/MAX1720/MAX1721 have a logic-con-
trolled shutdown input. Driving SHDNlow places the
MAX1720/MAX1721 in a low-power shutdown mode.
The MAX1719’s shutdown input is inverted from that of
the MAX1720/MAX1721. Driving SHDN high places the
MAX1719 in a low-power shutdown mode. The charge-
pump switching halts, supply current is reduced to
1nA, and OUT is actively pulled to ground through a 4Ω
resistance.
Applications Information
Capacitor SelectionTo maintain the lowest output resistance, use capaci-
tors with low ESR (Table 1). The charge-pump output
resistance is a function of C1’s and C2’s ESR.
Therefore, minimizing the charge-pump capacitor’s
ESR minimizes the total output resistance. Table 2
gives suggested capacitor values for minimizing output
resistance or minimizing capacitor size.1
fC12R4ESRESROUT
OSCC1C2≅()×+++
η≅+−×I
OUT
OUTQ
OUTOUT S4
VOUT = -(VIN)
Figure 2. Ideal Voltage InverterRL
VOUT
Figure 3a. Switched-Capacitor Model
REQUIV =
REQUIV
VOUT
f × C1C2
Figure 3b. Equivalent Circuit
NOTE: ( ) CAPACITORS ARE FOR MAX1720.*ON/OFF POLARITY OF SHDN IS REVERSED FOR MAX1719.
1μF (10μF)
1μF (10μF)ON
OFF
1μF (10μF)
C1+C1-
SHDN
OUT
GND
INPUT
1.5V to 5.5VNEGATIVE
OUTPUT
-1 ·VIN
25mA
MAX1719*
MAX1721
Figure 1. Typical Application Circuit
