Electrical characteristics (continued) – Rainbow Electronics MAX8707 User Manual
Page 4
MAX8707
Multiphase, Fixed-Frequency Controller for
AMD Hammer CPU Core Power Supplies
4
_______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1. V
CC
= V
SHDN
= 5V, OSC = REF, V
VPS
= V
FBS
= V
CRSN
= V
CRSP
= V
CSP_
= 1.20V, V
SUSV
= 0.8V, OFS = SUS =
GNDS = PGND = SKIP = GND, D0–D4 set for 1.20V (D0–D4 = 01110). T
A
= 0°C to +85°C, unless otherwise specified. Typical values
are at T
A
= +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
CC
Undervoltage-Lockout
Threshold
V
UVLO(VCC)
Rising edge, hysteresis = 20mV, PWM_
disabled below this level
4.10
4.25
4.45
V
Thermal-Shutdown Threshold
T
SHDN
Rising edge hysteresis = 15
°C
+160
°C
DROOP AND TRANSIENT RESPONSE
DC Droop Amplifier Offset
-1.5
+1.5
mV
DC Droop Amplifier
Transconductance
(CRS Sense Enabled)
G
m(VPS)
∆I
VPS
/ (N x
∆V
CRS
), V
VPS
= V
CRSN
= 1.2V,
V
CRSP
- V
CRSN
= -60mV to +60mV,
N = number of phases enabled
194
200
206
µS
DC Droop Amplifier
Transconductance
(CRS Sense Disabled)
G
m(VPS)
∆I
VPS
/ (
Σ∆V
CS
), V
CRSP
= V
CC
,
V
VPS
= V
CSN
_ = 1.2V,
V
CSP
_ – V
CSN
_ = -60mV to +60mV
194
200
206
µS
Transient-Droop Transresistance
R
TRANS
Current-sense gain (A
CS
= 10 typ) divided
by the voltage preamplifier
transconductance (G
m(TRC)
= 2ms typ)
4.75
5.0
5.25
k
Ω
Transient Detection Threshold
Measured at VPS with respect to steady-
state VPS regulation voltage; falling edge,
5.5mV hysteresis (typ)
-30
-25
-20
mV
CURRENT LIMIT AND BALANCE
Current-Sense Input Preamplifier
Offsets
CSP_ - CSN_
-2.0
+2.0
mV
ILIM(AVE)
Input Range
(Adjustable Mode)
V
ILIM(AVE)
V
REF
- 1.0
V
REF
- 0.2
V
ILIM(AVE) Average Current-Limit
Threshold Voltage
(Positive, Default)
V
AVELIMIT
CRSP - CRSN; ILIM(AVE)
= V
CC
22
25
28
mV
V
ILIM(AVE)
= V
REF
- 0.2V
7
10
13
ILIM(AVE) Average Current-Limit
Threshold Voltage
(Positive, Adjustable)
V
AVELIMIT
CRSP - CRSN
V
ILIM(AVE)
= V
REF
- 1.0V
46
50
54
mV
ILIM(AVE)
Average Current-Limit
Threshold Voltage (Negative)
CRSP - CRSN; ILIM(AVE) = V
CC
-30
-25
-20
mV
ILIM(AVE) Input Current
I
ILIM(AVE)
-0.1
+0.1
µA
ILIM(AVE) Current-Limit Default
Switchover Threshold
3
V
CC
- 1.0
V
CC
- 0.4
V
V
PKLIMIT
= 30mV
24
30
36
ILIM(PK)
Peak Current-Limit
Threshold Voltage (Positive)
V
PKLIMIT
CSP_ - CSN_,
R
ILIM(PK)
= R
TRC
x
8V / V
LIM(PK)
V
PKLIMIT
= 50mV
40
50
60
mV
ILIM(PK) Peak Current-Limit
Threshold Voltage (Negative)
CSP_ - CSN_, R
ILIM(PK)
= R
TRC
x 8V /
V
PKLIMIT
, V
PKLIMIT
= 50mV
-60
-50
-40
mV