PI1004-1 Datasheet, PDF (10/16 Pages) Vicor Corporation – Programmable Point-of-Load Controller with 6-bit VID

24
23
Vcc
21
VCC
19
EAO
{VID Signal
or
Hard Wired
VID Code
VID Pull-up
1 _VID0
2 _VID1
3 _VID2
4 _VID3
5 _VID4
6 _VID5
18
EAIN
REFOUT ²⁰
PI1004-1
17
EAIP
IAVP ¹⁵
13
ISP
R_{Bit 7}
R2
R1 _1mA
R_{Bit 7}
R_AVP
.
250
6.25
*
Inverted
Q1 Q2
2N2222 R_offset
8 _OFFSET
10 11
C2
12
ISN
RG ¹⁴
16 22
Vou t
R_AVP
} ^Rsense
R_G
Out -
Note: Inverted forced Beta of Q2
βI = ^IE ≤ 0.01
IB
Example
IEQ2 = 10µA
IB =
10µ A
0.01
=1mA
R2 = ^{VIDpullup – 0.6V}
IB
R1 = 10 • R2
Figure 4d - Application circuit using the AVP and Offset
features of the PI1004-1 plus optional 7 Bit resolution.
Component value selection for AVP, Offset and 7 Bit resolution
a. Select AVP droop voltage at full load
b. Select IAVP droop current at full load (200µA max)
c. Select current sense input voltage at maximum load (VISP – VISN)
d. Select VOffset voltage level to center DAC voltage
e. Add VID6 (seven bit) resolution Q1, Q2 circuit
Example
ΔVDROOP = 100mV
ΙAVP = 100µA
VSENSE = 120mV
VOFFSET = 25mV
1.
RAVP
=
ΔVdroop
=
100mV
=
1KΩ
IAVP 100µA
2.
RG
=
4•VSense
=
4•120mV
=
4.8KΩ
IAVP 100µA
3.
ROffset
250mV•RAVP
=
= ^{250mV•1KΩ} = 10KΩ
VOffset
25mV
250mV
250mV
4. RBit7 =
• RAVP =
• 1KΩ = 40KΩ
6.25mV
6.25mV
250mV 250mV
5. IEQ2 =
=
= 6.25µA
RBit7
40KΩ
See R1 and R2 Note above.
Picor Corporation • picorpower.com
PI1004 Data Sheet Rev. 2.5 Page 10 of 16