MAX771ESA+ Maxim Integrated Products, MAX771ESA+ Datasheet - Page 7

• Manufacturer Part Number: MAX771ESA+
• Description: IC CNTRLR DC-DC 8-SOIC
• Manufacturer: Maxim Integrated Products
• Type: Step-Up (Boost)r

Specifications of MAX771ESA+

• Internal Switch(s): No
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 12V, Adj
• Current - Output: 1A
• Frequency - Switching: 300kHz
• Voltage - Input: 2 ~ 16.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Power - Output: 471mW
• Output Voltage: 12 V or 3 V (Min)
• Output Current: 1 A (Max)
• Input Voltage: 2 V to 16.5 V
• Supply Current: 110 uA
• Switching Frequency: 300 KHz
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

(Circuit of Figure 2a, T
______________________________________________________________Pin Description
MAX770
MAX771
MAX772
____________________________Typical Operating Characteristics (continued)
—
—
—
—
—
1
2
3
4
5
6
7
8
PIN
MAX773
11
10
—
—
3
6
7
8
9
1
2
4
5
5V/12V/15V or Adjustable, High-Efficiency,
_______________________________________________________________________________________
A
= +25°C, unless otherwise noted.)
NAME
AGND
SHDN
SGND
GND
LBO
EXT
REF
V12
LBI
CS
V+
FB
V5
Gate drive for external N-channel power transistor
Power-supply input. Also acts as a voltage-sense point when in bootstrapped mode for the
MAX770/MAX771/MAX772, or as a shunt regulator when SGND is connected to ground for the
MAX773. Bypass to SGND with 0.1 F when using the shunt regulator.
Feedback input for adjustable-output operation. Connect to ground for fixed-output operation. Use
a resistor divider network to adjust the output voltage. See Setting the Output Voltage section.
Active-high TTL/CMOS logic-level shutdown input. In shutdown mode, V
below V+ (due to the DC path from V+ to the output) and the supply current drops to 5 A
maximum. Connect to ground for normal operation.
1.5V reference output that can source 100 A for external loads. Bypass to GND with 0.1 F.
The reference is disabled in shutdown.
Analog ground
High-current ground return for the output driver
Positive input to the current-sense amplifier. Connect the current-sense resistor between CS and GND.
Input sense point for 12V-output operation. Connect V
Leave unconnected for adjustable-output operation.
Input sense point for 5V-output operation. Connect V
unconnected for adjustable-output operation.
Low-battery output is an open-drain output that goes low when LBI is less than 1.5V. Connect to V+
through a pull-up resistor. Leave floating if not used. LBO is high impedance in shutdown mode.
Input to the internal low-battery comparator. Tie to GND or V+ if not used.
Shunt regulator ground. Leave unconnected if the shunt regulator is not used.
Low I
0
0
V
A: SHDN, 2V/div
B: V
IN
= 3V, I
OUT
, 2V/div
OUT
= 0.5A
Q
EXITING SHUTDOWN
, Step-Up DC-DC Controllers
MAX770
200 s/div
FUNCTION
A
B
OUT
OUT
to V5 for 5V-output operation. Leave
to V12 for 12V-output operation.
OUT
is a diode drop
7