MAX603CSA Maxim Integrated Products, MAX603CSA Datasheet - Page 7

• Manufacturer Part Number: MAX603CSA
• Description: IC LDO REG LOW-IQ 5V/ADJ 8-SOIC
• Manufacturer: Maxim Integrated Products

Specifications of MAX603CSA

• Regulator Topology: Positive Fixed or Adjustable
• Voltage - Output: 5V, 1.25 ~ 11 V
• Voltage - Input: 2.7 ~ 11.5 V
• Voltage - Dropout (typical): 0.32V @ 500mA
• Number Of Regulators: 1
• Current - Output: 500mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Number Of Outputs: 1
• Polarity: Positive
• Input Voltage Max: 11.5 V
• Output Voltage: 1.25 V to 11 V, 5 V
• Output Type: Adjustable, Fixed
• Dropout Voltage (max): 0.22 V at 200 mA
• Output Current: 500 mA
• Line Regulation: 7 mV
• Load Regulation: 60 mV
• Voltage Regulation Accuracy: 3 %
• Maximum Power Dissipation: 1.8 W
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: 0 C
• Reference Voltage: 1.2 V
• Case: SOP8
• Dc: 00+
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Limit (min): -

The MAX603/MAX604 feature dual-mode operation. In
preset voltage mode, the output of the MAX603 is set to
5V and the output of the MAX604 is set to 3.3V using
internal, trimmed feedback resistors. Select this mode
by connecting SET to ground.
In adjustable mode, an output between 1.25V and 11V
is selected using two external resistors connected as a
voltage divider to SET (Figure 3). The output voltage is
set by the following equation:
where V
Since the input bias current at SET is nominally zero,
large resistance values can be used for R1 and R2 to
minimize power consumption without losing accuracy. Up
to 1.5MΩ is acceptable for R2. Since the V
is less than ±40mV, the output can be set using fixed
resistors instead of trim pots.
In preset voltage mode, impedances between SET and
ground should be less than 10kΩ. Otherwise, spurious
conditions could cause the voltage at SET to exceed
the 80mV dual-mode threshold.
A low input on the OFF pin shuts down the MAX603/
MAX604. In the off mode, the pass transistor, control
circuit, reference, and all biases are turned off, reduc-
ing the supply current below 2µA. OFF should be con-
nected to IN for normal operation.
Use a fast comparator, Schmitt trigger, or CMOS or TTL
logic to drive the OFF pin in and out of shutdown. Rise
times should be shorter than 1µs. Do not use slow RC
circuits, leave OFF open, or allow the input to linger
between thresholds; these measures will prevent the
output from jumping to the positive supply rail in
response to an indeterminate input state.
Since the OFF threshold varies with input supply volt-
age (see Electrical Characteristics ), do not derive the
drive voltage from 3.3V logic. With V
high OFF logic level needs to be above 4V.
The MAX603/MAX604 also include a foldback current
limiter. It monitors and controls the pass transistor’s
gate voltage, estimating the output current and limiting
it to 1.2A for output voltages above 0.8V and V
SET
= 1.20V. To simplify resistor selection:
R1
V
OUT
_______________________________________________________________________________________
Foldback Current Limiting
R2
Output Voltage Selection
V
SET
V
V
5V/3.3V or Adjustable, Low-Dropout,
OUT
SET
1
- 1
Low I
R2
R1
IN
at 11.5V, the
SET
Shutdown
tolerance
IN
Q
- V
, 500mA Linear Regulators
OUT
> 0.7V. For V
is no current limit. If the output voltage drops below
0.8V, implying a short-circuit condition, the output cur-
rent is limited to 350mA. The output can be shorted to
ground for one minute without damaging the device if
the package can dissipate V
exceeding T
Thermal overload protection limits total power dissipa-
tion in the MAX603/MAX604. When the junction temper-
ature exceeds T
signal to the shutdown logic, turning off the pass tran-
sistor and allowing the IC to cool. The thermal sensor
will turn the pass transistor on again after the IC’s junc-
tion temperature cools by 10°C, resulting in a pulsed
output during thermal overload conditions.
Thermal overload protection is designed to protect the
MAX603/MAX604 in the event of fault conditions. For
continual operation, the absolute maximum junction tem-
perature rating of T
Maximum power dissipation of the MAX603/MAX604
depends on the thermal resistance of the case and cir-
cuit board, the temperature difference between the die
junction and ambient air, and the rate of air flow. The
power dissipation across the device is P = I
V
where (T
the MAX603/MAX604 die junction and the surrounding
Figure 3. Adjustable Output Using External Feedback Resistors
OUT
Operating Region and Power Dissipation
). The resulting maximum power dissipation is:
BATTERY
J
- T
C
0.1 F to
10 F
J
IN
IN
A
= +150°C.
) is the temperature difference between
P
- V
J
MAX
= +160°C, the thermal sensor sends a
Thermal Overload Protection
OUT
J
OFF
IN
= +150°C should not be exceeded.
MAX603
MAX604
< 0.7V (dropout operation), there
GND
OUT
SET
JB
T - T
J
+
IN
A
BA
R1
R2
x 350mA without
C
10 F
OUT
OUT
OUTPUT
VOLTAGE
R
L
(V
IN
7
-