AFL120XXD Series
Internally, these ports differ slightly in their function. In use,
a low on Enable 1 completely shuts down all circuits in the
converter, while a low on Enable 2 shuts down the secondary
side while altering the controller duty cycle to near zero.
Externally, the use of either port is transparent to the user
save for minor differences in idle current. (See specification
table).
which has been designated as the master oscillator provides
a convenient frequency source for this mode of operation.
When external synchronization is not indicted, the sync in
pin should be left unconnected thereby permitting the
converter to operate at its’ own internally set frequency.
The sync output signal is a continuous pulse train set at
550 ± 50KHz, with a duty cycle of 15 ± 5.0%. This signal is
referenced to the input return and has been tailored to be
compatible with the AFL sync input port. Transition times
are less than 100ns and the low level output impedance is
less than 50Ω. This signal is active when the DC input
voltage is within the specified operating range and the
converter is not inhibited. This synch output has adequate
drive reserve to synchronize at least five additional
converters. A typical synchronization connection option is
illustrated in Figure III.
Synchronization of Multiple Converters
When operating multiple converters, system requirements
often dictate operation of the converters at a common
frequency. To accommodate this requirement, the AFL
series converters provide both a synchronization input and
output.
The sync input port permits synchronization of an AFL
converter to any compatible external frequency source
operating between 500KHz and 700KHz. This input signal
should be referenced to the input return and have a 10% to
90% duty cycle. Compatibility requires transition times less
than 100ns, maximum low level of +0.8V and a minimum
high level of +2.0V. The sync output of another converter
Figure III. Preferred Connection for Parallel Operation
1
12
Power
Input
Enable 2
Share
Vin
Rtn
Case
Trim
AFL
AFL
Enable 1
Sync Out
Sync In
- Output
Return
+ Output
7
6
1
Optional
Synchronization
Connection
Share Bus
12
Enable 2
Share
Vin
Rtn
Case
Trim
Enable 1
Sync Out
Sync In
- Output
Return
+ Output
to Negative Load
to Positive Load
7
6
1
12
Enable 2
Share
Vin
Rtn
Case
Trim
AFL
Enable 1
Sync Out
Sync In
- Output
Return
+ Output
7
6
(Other Converters)
feature of the AFL series operating in the parallel mode is
that in addition to sharing the current, the stress induced by
temperature will also be shared. Thus if one member of a
paralleled set is operating at a higher case temperature, the
current it provides to the load will be reduced as
compensation for the temperature induced stress on that
device.
Parallel Operation-Current and Stress Sharing
Figure III. illustrates the preferred connection scheme for
operation of a set of AFL converters with outputs operating
in parallel. Use of this connection permits equal current
sharing among the members of a set whose load current
exceeds the capacity of an individual AFL. An important
6
www.irf.com
5秒后页面跳转
PCF8574资料解读：主要参数分析、引脚说明
AD637数据手册解读：主要特性、引脚及其功能解读、电气参数
ADUM1201资料手册解读：参数分析、引脚说明、应用分析
一文带你了解压敏电阻器在直流电路中的过压保护作用
微信公众号
抖音公众号
浙公网安备 33010502006866号 浙ICP备10014259号-119
营业执照ICP证
数据手册
如果您发现信息不准确，
