ALTAIR05T-800 STMicroelectronics, ALTAIR05T-800 Datasheet - Page 18

• Manufacturer Part Number: ALTAIR05T-800
• Description: IC PRIMARY SWITCHING REG 16NSOIC
• Manufacturer: STMicroelectronics

Specifications of ALTAIR05T-800

• Output Isolation: Isolated
• Voltage - Input: 11.5 ~ 23 V
• Voltage - Output: 800V
• Power (watts): 900mW
• Operating Temperature: -25°C ~ 125°C
• Package / Case: 16-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Application information
5.7
18/28
Figure 16. Feedforward compensation: internal schematic
The R
In this case the peak drain current does not depend on input voltage anymore.
One more consideration concerns the R
sourced by the ZCD/FB pin, I
µA typical).
If I
This feature is especially important when the auxiliary winding is accidentally disconnected
and considerably increases the end-product’s safety and reliability.
Cable drop compensation (CDC)
The voltage control loop regulates the output voltage as seen across the output capacitor.
If an output cable is used to supply the load, the voltage at the externally available terminals
is dependent on the output current value. The CDC function compensates the voltage drop
across the cable, so ideally zero load regulation can be achieved also at the end of the
cable.
ZCD
ZCD
< I
ZCDON
Aux
resistor can be calculated as follows:
R zcd
, the brownout function is activated and the IC is shut-down.
ZCD/FB
R f b
R
ZCD
ZCD
Doc ID 17957 Rev 1
F eedf orward
, is compared with an internal reference current I
Logic
=
N
N
AUX
PRI
ZCD
.
⋅
T R
d
L R
⋅
P
I FF
value: during MOSFET’s ON-time, the current
⋅
SENSE
FF
Block
C C
+
-
CC
Rf f
LOGI C
PWM
SOU RCE
DRAIN
ALTAIR05T-800
(4)
Rsense
ZCDON
(-50