MAX6841HUKD1+T Maxim Integrated, MAX6841HUKD1+T Datasheet - Page 7

• Manufacturer Part Number: MAX6841HUKD1+T
• Description: Supervisory Circuits
• Manufacturer: Maxim Integrated
• Series: MAX6841, MAX6842, MAX6843, MAX6844, MAX6845r

Specifications of MAX6841HUKD1+T

• Number Of Voltages Monitored: 1
• Monitored Voltage: 0.9 V to 1.5 V
• Undervoltage Threshold: 1.275 V
• Overvoltage Threshold: 1.35 V
• Output Type: Active High, Active Low, Push-Pull
• Manual Reset: Resettable
• Watchdog: No Watchdog
• Battery Backup Switching: No Backup
• Power-up Reset Delay (typ): 2 ms
• Supply Voltage - Max: 1.8 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SOT-23
• Chip Enable Signals: No
• Maximum Power Dissipation: 571 mW
• Minimum Operating Temperature: - 40 C
• Power Fail Detection: No
• Supply Current (typ): 8.1 uA
• Supply Voltage - Min: 0.75 V

dielectric. The input capacitor filters peak currents and
noise at the voltage source and, therefore, must meet
the input ripple requirements and voltage rating.
Calculate the maximum RMS input current as:
The output capacitor, C
tantalum depending upon the chosen application cir-
cuit (see Figures 1 through 4). Table 3 lists some sug-
gested capacitor suppliers.
For ceramic C
or Figure 2. Calculate the minimum capacitor value as:
Select the next standard value larger than C
The C
for capacitor tolerance. Values much larger than
C
stability, but capacitor size and cost increase.
Figure 2. Typical Application Circuit (MAX1920)
2V TO 5.5V
OUT
INPUT
C
OFF
IN
I
(MIN) always improve transient performance and
ON
IN
OUT
(
RMS
(MIN) calculation already includes a margin
1
2
3
C
)
OUT
IN
AGND
SHDN
OUT
=
I
MAX1920
OUT
(
, use the application circuit of Figure 1
MIN
_______________________________________________________________________________________
(
MAX
)
PGND
=
LX
FB
OUT
2 5 10
)
.
6
5
4
×
Ceramic Output Capacitor
, may be either ceramic or
×
V
OUT IN
−
6
R1
R2
×
(
V
V
V
C
IN
Low-Voltage, 400mA Step-Down
CRITICAL
L
FF
−
V
OUT
OUT
UP TO 400mA
)
OUTPUT
DC-DC Converters in SOT23
C
(MIN).
OUT
For tantalum C
3 or Figure 4. With tantalum C
resistance (ESR) of C
bility. Generally, 25mV of ESR-ripple at the feedback
node is sufficient. The simplified calculation is:
Because tantalum capacitors rarely specify minimum
ESR, choose a capacitor with typical ESR that is about
twice as much as ESR
greater than this work, output ripple becomes larger.
For tantalum C
capacitance as:
The 1.25 multiplier is for capacitor tolerance. Select any
standard value larger than C
The MAX1921 has factory preset output voltages of
1.5V, 1.8V, 2.5V, 3V, and 3.3V, while the MAX1920 is
externally adjusted by connecting FB to a resistive volt-
age-divider. When using a ceramic output capacitor,
the feedback network must include a compensation
feed-forward capacitor, C
Figure 3. MAX1921 Application Circuit Using Tantalum Output
Capacitor
2V TO 5.5V
INPUT
C
OFF
IN
C
ON
OUT
(
MIN
1
2
3
ESR
IN
AGND
SHDN
OUT
)
MAX1921
=
OUT
COUT
1 25
Feedback and Compensation
, use the application circuit of Figure
.
, calculate the minimum output
OUT
PGND
(
×
OUT
MIN
LX
ESR
COUT
FF
must be large enough for sta-
Tantalum Output Capacitor
6
5
4
)
.
=
COUT
OUT
OUT
8 0 10
.
L I
(MIN). Although ESRs
(MIN).
L
×
×
, the equivalent series
(
OUT
MIN
−
2
)
(
MAX
×
×
V
V
CRITICAL
OUT
)
UP TO 400mA
OUTPUT
C
OUT
7