TEA1998TS
GreenChip synchronous rectifier controller
Rev. 1 — 16 February 2017
Product data sheet
COMPANY PUBLIC
1
General description
The TEA1998TS is a member of a new generation of Synchronous Rectifier (SR)
controller ICs for switched mode power supplies with adaptive gate drive for maximum
efficiency at any load.
The TEA1998TS is a dedicated controller IC for synchronous rectification on the
secondary side of flyback converters. It incorporates the sensing stage and driver stage
for driving the SR MOSFET, which is rectifying the output of the secondary transformer
winding.
The TEA1998TS can generate its own supply voltage for battery charging applications
with low output voltage or for applications with high-side rectification.
The TEA1998TS is fabricated in a Silicon-On-Insulator (SOI) process.
2
Features and benefits
2.1 Efficiency features
•
Adaptive gate drive for maximum efficiency at any load
•
Typical supply current in no-load operation below 250 μA
2.2 Application features
•
•
•
•
•
•
•
Operates in an output voltage range between 10 V and 0 V
Drain sense pin capable of handling input voltages up to 60 V
Self-supplying for operation with low output voltage
Self-supplying for high-side rectification without the use of an auxiliary winding
Operates with standard and logic level SR MOSFETs
Supports USB BC, QuickCharge and smart charging applications
TSOP6 package
2.3 Control features
•
Adaptive gate drive for fast turn-off at the end of conduction
•
UnderVoltage LockOut (UVLO) with active gate pull-down
NXP Semiconductors
GreenChip synchronous rectifier controller
TEA1998TS
3
Applications
The TEA1998TS is intended for flyback power supplies. In such applications, it can drive
the external synchronous rectifier MOSFET, which replaces the diode for the rectification
of the voltage on the secondary winding of the transformer.
It can be used in all power supplies that require a high efficiency, like:
•
Chargers
•
Adapters
•
Flyback power supplies with very low and/or variable output voltage
4
Ordering information
Package
Name
Description
plastic surface-mounted package; 6 leads
Table 1. Ordering information
Type number
TEA1998TS
Version
SOT457
TSOP6
5
Marking
Table 2. Marking codes
Type number
TEA1998TS/1
Marking code
TEA1998
TEA1998TS
All information provided in this document is subject to legal disclaimers.
© NXP Semiconductors N.V. 2017. All rights reserved.
Product data sheet
COMPANY PUBLIC
Rev. 1 — 16 February 2017
2 / 18
NXP Semiconductors
GreenChip synchronous rectifier controller
TEA1998TS
6
Block diagram
CAP
UNDER
VOLTAGE
LOCKOUT
XV
Ich(CAP)
V AND I
REFERENCE
TEA1998
ENERGY
SAVE
CONTROL
LOGIC
enable
BLANKING
turn-on
on regulation
off regulation
DRAIN
TURN-ON
GATE
SWITCH-OFF
-400 mV
-25 mV
-20 mV
+250 mV
SOURCE
GND
-
-
-
-
aaa-022802
Figure 1. TEA1998TS block diagram
TEA1998TS
All information provided in this document is subject to legal disclaimers.
© NXP Semiconductors N.V. 2017. All rights reserved.
Product data sheet
COMPANY PUBLIC
Rev. 1 — 16 February 2017
3 / 18
NXP Semiconductors
GreenChip synchronous rectifier controller
TEA1998TS
7
Pinning information
7.1 Pinning
CAP
1
6
DRAIN
GND
2
IC
5
SOURCE
XV
3
aaa-021171
4
GATE
Figure 2. TEA1998TS pin configuration (SOT457)
7.2 Pin description
Table 3. Pin description
Symbol
CAP
GND
XV
GATE
SOURCE
DRAIN
Pin
1
2
3
4
5
6
Description
capacitor input for internal supply voltage
ground
external supply input
gate driver output for SR MOSFET
source sense input of SR MOSFET
drain sense input of SR MOSFET
TEA1998TS
All information provided in this document is subject to legal disclaimers.
© NXP Semiconductors N.V. 2017. All rights reserved.
Product data sheet
COMPANY PUBLIC
Rev. 1 — 16 February 2017
4 / 18
NXP Semiconductors
GreenChip synchronous rectifier controller
TEA1998TS
8
Functional description
8.1 Introduction
The TEA1998TS is a controller IC for Synchronous Rectification (SR) in flyback
applications. It can drive the external synchronous rectifier MOSFET for the rectification
of the voltage on the secondary winding of the transformer.
Figure 3
shows a typical
configuration.
SR low side
VCC
HV
GND
CTRL
PROTECT
8
2
6
7
PRIMARY
CONTROLLER
3
4
5
1
DRIVER
ISENSE
AUX
VCC
DRAIN
GATE
TEA1998
SOURCE
GATE
aaa-022803
S1
SECONDARY OPTO
CONTROLLER
XV
CAP
GND
Figure 3. TEA1998TS configuration with low-side rectification
8.2 Start-up and UnderVoltage LockOut (UVLO; CAP and XV pins)
The capacitor on the CAP pin supplies the TEA1998TS. When the XV voltage < 4.7 V,
the capacitor is charged via the DRAIN pin. When the XV voltage ≥ 4.7 V, the capacitor
is charged via the XV pin and an internal regulator. The regulator reduces the voltage
difference between the XV and CAP pins to a level below 100 mV.
When the voltage on the CAP pin exceeds V
start(CAP)
(3.7 V typical), the IC leaves the
UVLO state and activates the synchronous rectifier circuitry. When the voltage drops
below 3.6 V (typical), the UVLO state is reentered and the SR MOSFET gate driver
output is actively kept low.
8.3 Drain sense (DRAIN pin)
The drain sense pin is an input pin capable of handling input voltages up to 60 V. At
positive drain sense voltages, the gate driver is in off-mode with the gate driver pulled
down (pin GATE). At negative drain sense voltages, the IC enables the Synchronous
Rectification (SR) by sensing the drain source differential voltage.
TEA1998TS
All information provided in this document is subject to legal disclaimers.
© NXP Semiconductors N.V. 2017. All rights reserved.
Product data sheet
COMPANY PUBLIC
Rev. 1 — 16 February 2017
5 / 18
京公网安备 11010802033920号
EEWORLD
