tp2150b Tripath Technology Inc., tp2150b Datasheet - Page 12

• Manufacturer Part Number: tp2150b
• Description: Dual High Side And Low Side Mosfet Driver
• Manufacturer: Tripath Technology Inc.

the internal VN10 generator to power the TP2150B. Figure 6 shows how the VN10 generator
should be connected.
In some cases, though, a designer may wish to use an external VN10 generator.
specification for VN10 quiescent current (100mA typical) in the Electrical Characteristics section
states the amount of current needed when an external floating supply is used. If the internal VN10
generator is not used then short the CSS pin to (pin 9) disable this feature.
One apparent method to generate the VN10 supply voltage is to use a negative IC regulator to
drop PGND down to 10V (relative to VNN). This method will not work since negative regulators
only sink current into the regulator output and will not be capable of sourcing the current required
by VN10. Furthermore, problems can arise since VN10 will not track movements in VNN. The
external VN10 supply must be able to source a minimum of 200mA into the VN10 pin.
positive supply must be used and must be referenced to the VNN rail. If the external VN10 supply
does not track fluctuations in the VNN supply or is not able to source current into the VN10 pin, the
TP2150B will not work and can also become permanently damaged.
Figure 7 shows the correct way to power the TP2150B:
12
Power Supply
TP2150B
Switchm ode
VN10
VNN
VPP
Figure 7: Proper Power Supply Connection
59
60
PGND
Figure 6: VN10 Generator
SM PSO
SW -FB
C
0.1uF
10V
SW FB
F. BEAD
5V
VNN
R
R
PG
SW FB
10
T r i p a t h T e c h n o l o g y , I n c . - T e c h n i c a l I n f o r m a t i o n
:
1k
B1100DICT
:
Q
P
D
VPP
V5
AGND
VN10
VNN
SW
100uH
L
SW
C
0.1uF
SW
TP2150B - MC/ 1.7/06.04
+
C
100uF
SW
VN10
VNN
Thus, a
The