TNY263-268
BYPASS
(BP)
REGULATOR
5.8 V
LINE UNDER-VOLTAGE
240 A
50 A
FAULT
PRESENT
DRAIN
(D)
+
-
CURRENT
LIMIT STATE
MACHINE
5.8 V
4.8 V
BYPASS PIN
UNDER-VOLTAGE
AUTO-
RESTART
COUNTER
6.3 V
RESET
VI
LIMIT
CURRENT LIMIT
COMPARATOR
ENABLE
-
+
JITTER
CLOCK
1.0 V + VT
DCMAX
THERMAL
SHUTDOWN
OSCILLATOR
ENABLE/
UNDER-
VOLTAGE
(EN/UV)
1.0 V
S
Q
R
Q
LEADING
EDGE
BLANKING
SOURCE
(S)
PI-2643-030701
Figure 2.
Functional Block Diagram.
Pin Functional Description
DRAIN (D) Pin:
Power MOSFET drain connection. Provides internal operating
current for both start-up and steady-state operation.
BYPASS (BP) Pin:
Connection point for a 0.1
μF
external bypass capacitor for the
internally generated 5.8 V supply.
ENABLE/UNDERVOLTAGE (EN/UV) Pin:
This pin has dual functions: enable input and line undervoltage
sense. During normal operation, switching of the power
MOSFET is controlled by this pin. MOSFET switching is
terminated when a current greater than 240
μA
is drawn from
this pin. This pin also senses line undervoltage conditions
through an external resistor connected to the DC line voltage.
If there is no external resistor connected to this pin,
TinySwitch-II detects its absence and disables the line
undervoltage function.
SOURCE (S) Pin:
Control circuit common, internally connected to output
MOSFET source.
P Package (DIP-8B)
G Package (SMD-8B)
BP
S
S
EN/UV
1
2
3
4
8
7
S (HV RTN)
S (HV RTN)
5
D
PI-2685-101600
Figure 3.
Pin Configuration.
SOURCE (HV RTN) Pin:
Output MOSFET source connection for high voltage return.
2
Rev. H 02/09
www.powerint.com
POWERINT [ POWER INTEGRATIONS, INC. ]
