ISL28006 Datasheet, PDF (19/25 Pages) Intersil Corporation – Micropower, Rail to Rail Input Current Sense Amplifier with Voltage Output

ISL28006
The input gm stage derives its ~2.86µA supply current
from the input source through the R_S+ terminal as long
as the sensed voltage at the R_S+ pin is >1.35V and the
gm_HI amplifier is selected. When the sense voltage at
R_S+ drops below the 1.35V threshold, the gm_LO
amplifier kicks in and the gm_LO output current reverses,
flowing out of the R_S- pin.
OPTIONAL
FILTER
CAPACITOR
I_{S +}
R_S
-
R_S+
V_SENSE
R_S-
OPTIONAL
TRANSIENT
PROTECTION
LOAD
I = 2.86µA
V_SENSE
R₁
gm_HI
V_CC
HIGH-SIDE
SENSING
V_RS+ = 2V TO 28V
R₂
1.35V
R₃
gm_{LO ‘VSENSE}
+
-
R_f
R₅
R_g
I_MIRROR
R₄
GND
V_CC = 2V to 28V
OUT
F_B
ADJ
OPTION
ONLY
FIGURE 66. HIGH-SIDE CURRENT DETECTION
OPTIONAL
FILTER
CAPACITOR
I_{S +}
R_S
-
R_S+
V_SENSE
R_S-
OPTIONAL
TRANSIENT
PROTECTION
LOAD
I = 2.86µA
V_SENSE
R₁
gm_HI
V_CC
LOW-SIDE
SENSING
V_RS+= 0V TO 2V
R₂
1.35V
V_CC
R₃
gm_LO
+
-
R_f
R₅
R_g
I_MIRROR ^‘VSENSE
R₄
GND
V_CC = 2V TO 28V
OUT
F_B
ADJ
OPTION
ONLY
FIGURE 67. LOW-SIDE CURRENT DETECTION
19
FN6548.3
May 27, 2010