LT3991EMSE-5#PBF Linear Technology, LT3991EMSE-5#PBF Datasheet - Page 8

• Manufacturer Part Number: LT3991EMSE-5#PBF
• Description: IC, DC-DC CONV, 2MHz, MSOP10
• Manufacturer: Linear Technology

Specifications of LT3991EMSE-5#PBF

• Primary Input Voltage: 55V
• No. Of Outputs: 1
• Output Voltage: 5V
• Output Current: 1.2A
• No. Of Pins: 10
• Operating Temperature Range: -40°C To +125°C
• Peak Reflow Compatible (260 C): Yes
• Msl: MSL 1 - Unlimited
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PG (Pin 9): The PG pin is the open-drain output of an
internal comparator. PGOOD remains low until the FB pin
is within 9% of the final regulation voltage. PGOOD is
valid when the LT3991 is enabled and V
SYNC (Pin 10): This is the external clock synchronization
input. Ground this pin for low ripple Burst Mode operation
LT3991/LT3991-3.3/LT3991-5
PIN FUNCTIONS
BLOCK DIAGRAM
8
V
IN
C1
R
T
V
EN
RT
SYNC
PG
IN
GND
1V
+
–
INTERNAL 1.19V REF
+
–
SHDN
R2
1.09V
FB
R1
C5
ERROR AMP
LT3991
ONLY
+
–
IN
Σ
R2
is above 4.3V.
200kHz TO 2MHz
V
C5
SLOPE COMP
R1
OSCILLATOR
C
LT3991-3.3
V
LT3991-5
–
+
OUT
ONLY
Burst Mode
V
C
DETECT
CLAMP
at low output loads. Tie to a clock source for synchroni-
zation, which will include pulse-skipping at low output
loads. When in pulse-skipping mode, quiescent current
increases to 1.5mA.
GND (Exposed Pad Pin 11): Ground. The exposed pad
must be soldered to PCB.
R
S
SWITCH
LATCH
Q
SHDN
1µA
BOOST
SW
BD
SS
D1
C3
C4
L1
3991 BD
C2
3991fa
V
OUT