MAX1719EUT+T Maxim Integrated Products, MAX1719EUT+T Datasheet - Page 5

• Manufacturer Part Number: MAX1719EUT+T
• Description: IC VOLT INV SW CAP SOT23-6
• Manufacturer: Maxim Integrated Products
• Type: Switched Capacitor (Charge Pump), Invertingr

Specifications of MAX1719EUT+T

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: -1.5 ~ -5.5 V
• Current - Output: 25mA
• Frequency - Switching: 125kHz
• Voltage - Input: 1.5 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-6
• Power - Output: 696mW
• Function: Inverting
• Output Voltage: - 1.4 V to - 5.5 V
• Output Current: 25 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The 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-
(Circuit of Figure 1, V
otherwise noted.)
R
MAX1719
L
= 1kΩ
START-UP FROM SHUTDOWN
1
2
3
4
5
6
–
PIN
MAX1721
50µs/div
MAX1720
MAX1721
_______________________________________________________________________________________
IN
1
2
3
4
5
6
–
= +5V, SHDN = GND (MAX1719), SHDN = IN (MAX1720/MAX1721), C1 = C2 = C3, T
Detailed Description
MAX1720/21toc13
NAME
SHDN
SHDN
GND
OUT
C1+
C1-
V
2V/div
V
5V/div
IN
OUT
SHDN
Voltage Inverters with Shutdown
35
30
25
20
15
10
Inverting Charge-Pump Output
Power-Supply Positive Voltage Input
Negative Terminal of Flying Capacitor
Ground
Noninverting Shutdown Input. Drive this pin low for normal operation; drive it high for
shutdown mode. OUT is actively pulled to ground during shutdown.
Inverting Shutdown Input. Drive this pin high for normal operation; drive it low for
shutdown mode. OUT is actively pulled to ground during shutdown.
Positive Terminal of Flying Capacitor
Typical Operating Characteristics (continued)
5
0
0
OUTPUT CURRENT vs. CAPACITANCE
0.5
SOT23, Switched-Capacitor
1.0 1.5 2.0 2.5
MAX1719/MAX1721
CAPACITANCE (µF)
V
V
V
IN
IN
IN
= +4.75V, V
= +3.15V, V
= +1.9V, V
cycle, S1 and S3 open, S2 and S4 close, and C1 is level
shifted downward by V
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
-V
than -V
load drains charge from C2.
3.0 3.5 4.0 4.5 5.0
IN
. The actual voltage at the output is more positive
OUT
OUT
OUT
= -4.0V
= -2.5V
= -1.5V
IN
, since switches S1–S4 have resistance and the
FUNCTION
400
350
300
250
200
150
100
50
0
OUTPUT VOLTAGE RIPPLE vs. CAPACITANCE
IN
0
0.5
volts. This connects C1 in par-
1.0 1.5 2.0 2.5
MAX1719/MAX1721
Pin Description
CAPACITANCE (µF)
A
V
V
V
IN
= +25°C, unless
IN
IN
= +4.75V, V
= +3.15V, V
= +1.9V, V
3.0 3.5 4.0 4.5 5.0
OUT
OUT
OUT
= -1.5V
= -4.0V
= -2.5V
5