tea1738t NXP Semiconductors, tea1738t Datasheet - Page 15

• Manufacturer Part Number: tea1738t
• Description: Tea1738t; Tea1738lt Greenchip Smps Control Ic
• Manufacturer: NXP Semiconductors

NXP Semiconductors
Table 5.
T
the IC; unless otherwise specified.
[1]
11. Application information
TEA1738T_TEA1738LT
Product data sheet
Symbol
I
I
V
Temperature protection
T
source(DRIVER)
sink(DRIVER)
amb
pl(IC)
O(DRIVER)max
The clamp voltage on the PROTECT pin is lowered when the IC is in Power-down mode (latched or restart protection).
= 25
°
C; V
Characteristics
CC
= 20 V; all voltages are measured with respect to ground (pin 2); currents are positive when flowing into
Parameter
source current on pin
DRIVER
sink current on pin
DRIVER
maximum output
voltage on pin DRIVER
IC protection level
temperature
A power supply with the TEA1738(L) is a flyback converter operating in Continuous
conduction mode (see
Capacitor C5 buffers the IC supply voltage, which is powered via resistor R3 at start-up
and via the auxiliary winding during normal operation. Sense resistor R9 converts the
current through the MOSFET S1 into a voltage on pin ISENSE. The value of resistor R9
defines the maximum primary peak current in MOSFET S1. Resistor R7 reduces the peak
current to capacitor C5.
In the example shown in
set by Negative Temperature Coefficient (NTC) resistor R4. If an (additional) external OVP
is required, a Zener diode can be connected between the VCC pin and the PROTECT pin.
The VINSENSE pin is used for mains voltage detection and resistors R1 and R2 set the
start voltage to about 80 V (AC).
The overpower protection time, defined by capacitor C4, is set to 60 ms.
The restart time is defined by capacitor C4 and resistor R8 at 0.5 s.
Resistor R6 and capacitor C6 define the soft start time. Resistor R5 prevents the soft start
capacitor C6 from being charged during normal operation due to negative voltage spikes
across the current sense resistor R9.
Capacitor C3 reduces the noise on the CTRL pin. Resistor R7 reduces the peak current to
capacitor C5.
Resistor R10 is required to limit the current spikes to the DRIVER pin due to parasitic
inductance of the current sense resistor R9.
…continued
All information provided in this document is subject to legal disclaimers.
Conditions
V
V
V
DRIVER
DRIVER
DRIVER
Rev. 2 — 14 January 2011
Figure
Figure
= 2 V
= 2 V
= 10 V
11).
11, the PROTECT pin is used for OTP. The OTP level is
TEA1738T; TEA1738LT
Min
-
0.25
0.6
9
130
Typ
−0.3
0.3
0.75
10.5
140
GreenChip SMPS control IC
Max
-0.25
-
-
12
150
© NXP B.V. 2011. All rights reserved.
Unit
A
A
A
V
°C
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