ISL6504 Datasheet, PDF (13/16 Pages) Intersil Corporation – Multiple Linear Power Controller with ACPI Control Interface

ISL6504, ISL6504A
Q1
The NPN transistor used as sleep state pass element on the
3.3V_DUAL output has to have a minimum current gain of 100
at 1.5V V_CE and 650mA I_CE throughout the in-circuit
operating temperature range. For larger current ratings on
the 3.3V_DUAL output (providing the ATX 5V_SB output rating
is equally extended), selection criteria for Q1 include an
appropriate current gain (h_fe) and saturation characteristics.
Q2, Q4
These N-Channel MOSFETs are used to switch the 3.3V
and 5V inputs provided by the ATX supply into the
3.3V_DUAL/3.3V_SB and 5V_DUAL outputs while in active (S0,
S1) state. The main criteria for the selection of these
transistors is output voltage budgeting. The maximum
r_DS(ON) allowed at highest junction temperature can be
expressed with the following equation:
r_DS(ON)max
=
V_{-----I--N----m-----i-n-----–----}V_{----O-----U----T----m----i--n- , where}
I_OUTmax
V_INmin - minimum input voltage
V_OUTmin - minimum output voltage allowed
I_OUTmax - maximum output current
Q3
If a P-Channel MOSFET is used to switch the 5V_SB output of
the ATX supply into the 5V_DUAL output during sleep states,
then the selection criteria of this device is proper voltage
budgeting. The maximum r_DS(ON), however, has to be
achieved with only 4.5V of gate-to-source voltage, so a logic
level MOSFET needs to be selected. If a PNP device is
chosen to perform this function, it has to have a low-
saturation voltage while providing the maximum sleep
current and have a current gain sufficiently high to be
saturated using the minimum drive current (typically 20mA).
ISL6504 Application Circuit
Figure 12 shows a typical application circuit for the
ISL6504/A. The circuit provides the 3.3V_DUAL/3.3V_SB
voltage, the ICH4 resume well 1.5V_SB voltage, the 1.2V_VID
voltage identification output, and the 5V_DUAL
keyboard/mouse voltage from +3.3V, +5V_SB, +5V, and
+12VDC ATX supply outputs. Q3 can also be a PNP
transistor, such as an MMBT2907AL. For additional, more
detailed information on the circuit, including a Bill-of-
Materials and circuit board description, see Application Note
AN1001. Also see Intersil Corporation’s web page
(www.intersil.com).
+5VIN
R1
+12VIN
1k
+3.3VIN
+5VSB
Q2
HUF76113T3S
+3.3VDUAL/3.3VSB
+ _C4
330mF
‘FAULT’
+1.5VSB
C5 ⁺
10mF
S3
S5
5VSB
16
3V3
5
3V3DLSB
2
Q1
2SD1802
C1
1mF
VID_PG
14
VID_CT
15
C2
0.1mF
3V3DL
3
U1
1V2VID
4
C3 ⁺
10mF
ISL6504/A
FAULT
9
5VDLSB
11
1V5SB
1
R3
1k
DLA
10
‘VID PGOOD’
R2
10k
+1.2VVID
Q3
FDV304P
Q4
HUF76113T3S
S3
6
S5
7
SS
13
C7
0.1mF
5VDL
12
+ _C6
220mF
8
GND
+5VDUAL
FIGURE 12. TYPICAL ISL6504/A APPLICATION DIAGRAM
13
FN9062.2
April 13, 2004