PTH04T220W Datasheet, PDF (29/39 Pages) Texas Instruments – 16-A, 2.2-V to 5.5-V INPUT, NON-ISOLATED, WIDE-OUTPUT, ADJUSTABLE POWER MODULE WITH TURBOTRANS

PTH04T220W, PTH04T221W
www.ti.com
SLTS275A – DECEMBER 2006 – REVISED FEBRUARY 2007
Notes on Use of Auto-Track™
1. The Track pin voltage must be allowed to rise above the module set-point voltage before the module
regulates at its adjusted set-point voltage.
2. The Auto-Track function tracks almost any voltage ramp during power up, and is compatible with ramp
speeds of up to 1 V/ms.
3. The absolute maximum voltage that may be applied to the Track pin is the input voltage V_I.
4. The module cannot follow a voltage at its track control input until it has completed its soft-start
initialization. This takes about 20 ms from the time that a valid voltage has been applied to its input.
During this period, it is recommended that the Track pin be held at ground potential.
5. The Auto-Track function is disabled by connecting the Track pin to the input voltage (V_I). When
Auto-Track is disabled, the output voltage rises according to its softstart rate after input power has been
applied.
6. The Auto-Track pin should never be used to regulate the module's output voltage for long-term,
steady-state operation.
V_I = 5 V
C4
0.1 µF
U3
6
V
3
CC
5
MR
SENSE
1
RESET
4 ^TPS3808G50
CT
GND
C3
2
4700 pF
U1
AutoTrack
TurboTrans
+Sense
V_I
+
C_I1
PTH04T230W
V_O
GND
−Sense
V_O Adj
R_SET1
1.21 kΩ
R_TT
Vo₁ = 3.3 V
C_O1
U2
AutoTrack
TurboTrans
+Sense
R_TT
V_I
PTH04T220W
V_O
+
C_I2
GND
−Sense
V_O Adj
R_SET2
4.75 kΩ
Vo₂ = 1.8 V
C_O2
Figure 27. Sequenced Power Up and Power Down Using Auto-Track
Submit Documentation Feedback
29