LTC1922EG-1#PBF Linear Technology, LTC1922EG-1#PBF Datasheet - Page 10

• Manufacturer Part Number: LTC1922EG-1#PBF
• Description: IC CTLR PWM SYNC 20SSOP
• Manufacturer: Linear Technology

Specifications of LTC1922EG-1#PBF

• Pwm Type: Voltage/Current Mode
• Number Of Outputs: 1
• Frequency - Max: 1MHz
• Duty Cycle: 99%
• Buck: No
• Boost: No
• Flyback: No
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: Yes
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-SSOP
• Frequency-max: 1MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -

OPERATIO
LTC1922-1
. a nd must be considered when specifying the power trans-
former. If ZVS is required over the entire range of loads, a
small commutating inductor is added in series with the
primary to aid with the passive leg transition, since the
leakage inductance alone is usually not sufficient and
predictable enough to guarantee ZVS over the full load
range.
10
State 1.
State 2.
State 3.
State 4.
U
MA
MB
MA
MB
MA
MB
MA
MB
POWER PULSE 1
POWER PULSE 2
TRANSITION
TRANSITION
PASSIVE
ACTIVE
V
IN
I
MC
MD
P
MC
MD
MC
MD
MC
MD
I
L01
/N + (V
N:1
IN
MF
MA
MB
MF
• T
Figure 1. ZVS Operation
OVL
)/L
ME
MAG
FREEWHEEL
INTERVAL
ME
L1
L2
State 4 (Power Pulse 2)
During power pulse 2, current builds up in the primary
winding in the opposite direction as power pulse 1. The
primary current consists of reflected output inductor
current and current due to the primary magnetizing induc-
tance. At the end of State 4, MOSFET MC turns off and an
active transition, essentially similar to State 2, but oppo-
site in direction (high to low) takes place.
+
+
MC
MD
V
LOAD
LOAD
V
OUT
OUT
1922 F01
MF
PRIMARY AND
SECONDARY SHORTED
ME
V
LOAD
OUT