SA58780 Datasheet, PDF (2/15 Pages) NXP Semiconductors – Sense current amplifier with selectable gain

Philips Semiconductors
Sense current amplifier with selectable gain
Product data
SA58780
GENERAL DESCRIPTION
The SA58780 is a single amplifier that allows current sensing
independent of the supply voltage. The input offset voltage is
typically ±500 µV with typical offset drift of ±6 µV/°C. The SA58780
supply current is typically 150 µA and it operates from 3.0 V to 24 V
single supply. The input common mode range is selectable for high
and low ranges. The amplifIer gain is user selected for a “High” of
100 V/V or a “Low” of 50 V/V.
The SA58780 is ideal for battery charger applications in notebook
computers and PDAs.
FEATURES
• Supply voltage range: 3 V to 24 V
• Low supply current: 150 µA (typical)
• Low input offset voltage: ±500 µV (typical)
• Low input offset drift: ±6 µV/°C (typical)
• Power supply rejection ratio (1 kHz): 80 dB (typical)
• Common mode rejection ratio (1 kHz): 100 dB (typical)
• Common mode input range selection:
1.8 V to 24 V (I_SEL HIGH);
–0.3 V to V_CC – 2.4 V (I_SEL LOW)
• Amplifier gain selection:
G_SEL HIGH: G_V = 100 V/V;
G_SEL LOW: G_V = 50 V/V
SIMPLIFIED DEVICE DIAGRAM
TO CHARGE
R_S
INPUT CONTROL
TO BATTERY
I_SEL
1
IN–
2
HIGH
IN+
3
V/I CONVERTER
LOW
GND
4
APPLICATIONS
• Notebook computers
• Personal digital assistants (PDA)
SA58780
H
L
R
200 kΩ
R
194 kΩ
R
6 kΩ
R
15 kΩ
R
10 kΩ
R
6 kΩ
R
5 kΩ
H
R
55 kΩ
L
H
L
R
5 kΩ
R
55 kΩ
Figure 1. Simplified device diagram.
GAIN CONTROL
8
G_SEL
7
V_CC
OUT
6
TO ADC
COM
5
V_COM
SL01575
2003 Nov 10
2