Datasheet

2
G
4/05
TNY263-268
Figure 2. Functional Block Diagram.
Figure 3. Pin Configuration.
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/UNDER-VOLTAGE (EN/UV) Pin:
This pin has dual functions: enable input and line under-voltage
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 under-voltage 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 under-
voltage function.
SOURCE (S) Pin:
Control circuit common, internally connected to output
MOSFET source.
SOURCE (HV RTN) Pin:
Output MOSFET source connection for high voltage return.
PI-2643-030701
CLOCK
OSCILLATOR
5.8 V
4.8 V
SOURCE
(S)
S
R
Q
DC
MAX
BYPASS
(BP)
+
-
V
I
LIMIT
FAULT
PRESENT
CURRENT LIMIT
COMPARATOR
ENABLE
LEADING
EDGE
BLANKING
THERMAL
SHUTDOWN
+
-
DRAIN
(D)
REGULATOR
5.8 V
BYPASS PIN
UNDER-VOLTAGE
1.0 V + V
T
ENABLE/
UNDER-
VOLTAGE
(EN/UV)
Q
240 µA 50 µA
LINE UNDER-VOLTAGE
RESET
AUTO-
RESTART
COUNTER
JITTER
1.0 V
6.3 V
CURRENT
LIMIT STATE
MACHINE
PI-2685-101600
EN/UV
D
S
S
S (HV RTN)
S (HV RTN)
BP
P Package (DIP-8B)
G Package (SMD-8B)
8
5
7
1
4
2
3