sip41109 Vishay, sip41109 Datasheet - Page 6

• Manufacturer Part Number: sip41109
• Description: Sip41109 - Half-bridge N-channel Mosfet Driver For Dc/dc Conversion
• Manufacturer: Vishay

where Q
high-side MOSFET and DV
droop allowed in the bootstrapped supply voltage when the
high-side MOSFET is driven high. The bootstrap capacitor
value is typically 0.1 mF to 1 mF. The bootstrap capacitor
voltage rating must be greater than V
transient spikes and ringing.
Shoot-Through Protection
The external MOSFETs are prevented from conducting at the
same time during transitions. Break-before-make circuits
monitor the voltages on the PHASE pin and the LGATE pin and
control the switching as follows: When the signal on PWM goes
low, UGATE will go low after an internal propagation delay.
After the voltage on PHASE falls below 2.5 V by the inductor
action, the low-side driver is enabled and LGATE goes high
after some delay. When the signal on PWM goes high, LGATE
will go low after an internal propagation delay. After the voltage
on LGATE drops below 2.5 V the high-side driver is enabled
and UGATE will go high after an internal propagation delay. If
PHASE does not drop below 2.5 V within 380 ns after UGATE
goes low, LGATE is forced high until the next PWM transition.
www.vishay.com
6
SiP41109/41110
Vishay Siliconix
TYPICAL CHARACTERISTICS
105
95
85
75
65
55
45
35
25
15
5
GATE
0
I
CC
is the gate charge needed to turn on the
V
CC
vs. C
1
= 12 V
1 MHz
LOAD
2
vs. Frequency (SiP41109)
BOOT
C
LOAD
− PHASE is the amount of
(nF)
500 kHz
3
CC
+ 12 V to withstand
200 kHz
4
5
New Product
V
MOSFET drivers draw large peak currents from the supplies
when they switch. A local bypass capacitor is required to
supply this current and reduce power supply noise. Connect
a 1-mF ceramic capacitor as close as practical between the
V
Undervoltage Lockout
Undervoltage lockout prevents control of the circuit until the
supply voltages reach valid operating levels. The UVLO circuit
forces LGATE and UGATE to low when V
specified voltage. A separate UVLO forces UGATE low when
the voltage between BOOT and PHASE is below the specified
voltage.
Thermal Protection
If the die temperature rises above 165_C, the thermal
protection disables the drivers. The drivers are re-enabled
after the die temperature has decreased below 140_C.
CC
CC
Bypass Capacitor
and GND pins.
100
90
80
70
60
50
40
30
20
10
0
0
I
CC
V
CC
vs. C
1
= 12 V
LOAD
1 MHz
vs. Frequency (SiP41110)
2
C
LOAD
(nF)
S-51104—Rev. A, 13-Jun-05
3
Document Number: 73023
500 kHz
CC
200 kHz
4
is below its
5