ISL8104 Intersil Corporation, ISL8104 Datasheet - Page 5

• Manufacturer Part Number: ISL8104
• Description: Synchronous Buck Pulse-Width Modulator (PWM) Controller
• Manufacturer: Intersil Corporation

Electrical Specifications
Typical Performance Curves
Functional Pin Description (SOIC/QFN)
RT (Pin 1/14)
This pin provides oscillator switching frequency adjustment.
By placing a resistor (R
switching frequency is set from between 200kHz and
1.5MHz according to the following equation:
REFERENCE
Reference Voltage
System Accuracy
REFIN Current Source (QFN Only)
REFIN Threshold (QFN Only)
REFIN Offset (QFN Only)
GATE DRIVERS
Upper Drive Source Current
Upper Drive Source Impedance
Upper Drive Sink Current
Upper Drive Sink Impedance
Lower Drive Source Current
Lower Drive Source Impedance
Lower Drive Sink Current
Lower Drive Sink Impedance
SSDONE (QFN ONLY)
SSDONE Low Output Voltage
R
RT
1000
[
kΩ
100
10
FIGURE 1. R
10
]
≈
PARAMETER
------------------------------------------------------ - 1.3kΩ
F
s
[
kHz
] 200 kHz
6500
–
R
SWITCHING FREQUENCY (kHz)
RT
RT
TO +14V
RT
RESISTANCE vs FREQUENCY
PULLUP
[
) from this pin to GND, the
R
RT
]
5
–
TO GND
PULLDOWN
Recommended Operating Conditions, unless otherwise noted specifications in bold are valid for process,
temperature, and line operating conditions. (Continued)
100
R
R
I
I
U_SOURCE
L_SOURCE
SYMBOL
U_SOURCE
L_SOURCE
R
R
I
I
U_SINK
L_SINK
U_SINK
L_SINK
(R
RT
to GND)
T
T
T
T
V
90mA Source Current
V
90mA Source Current
V
90mA Source Current
V
90mA Source Current
I
SSDONE
J
J
J
J
BOOT
BOOT
PVCC
PVCC
= 0°C to 70°C
= -40°C to 85°C
= 0°C to 70°C
= -40°C to 85°C
1000
= 14V, 3nF Load - GBD
= 14V, 3nF Load - GBD
- V
- V
= 2mA
ISL8104
PHASE
PHASE
TEST CONDITIONS
= 14V, 3nF Load - GBD
= 14V, 3nF Load - GBD
Alternately ISL8104’s switching frequency can be lowered
from 200kHz to 50kHz by connecting the RT pin with a
resistor to VCC according to the following equation:
R
RT
FIGURE 2. BIAS SUPPLY CURRENT vs FREQUENCY
80
70
60
50
40
30
20
10
[
0
kΩ
100
]
≈
------------------------------------------------------ -
200 kHz
200
C
[
GATE
300
55000
SWITCHING FREQUENCY (kHz)
] F
= 3300pF
–
0.591
0.588
400
MIN
2.10
-1.0
-1.5
s
-4
-3
[
-
-
-
-
-
-
-
-
kHz
500
]
+
0.597
0.597
70kΩ
TYP
1.25
0.94
2.0
1.3
1.3
600
-6
2
2
3
-
-
-
-
C
C
GATE
GATE
700
= 10pF
0.603
0.606
MAX
= 1000pF
3.50
0.30
1.0
1.5
(R
-8
3
-
-
-
-
-
-
-
-
800
RT
February 13, 2006
to VCC)
900
UNITS
mV
FN9257.0
µA
%
%
Ω
Ω
Ω
Ω
V
V
V
A
A
A
A
V
1000