CS5460A-BSZ Cirrus Logic Inc, CS5460A-BSZ Datasheet - Page 37

• Manufacturer Part Number: CS5460A-BSZ
• Description: IC ENERGY METERING 1PHASE 24SSOP
• Manufacturer: Cirrus Logic Inc

Specifications of CS5460A-BSZ

• Package / Case: 24-SSOP
• Input Impedance: 30 KOhm
• Measurement Error: 0.1%
• Voltage - I/o High: 0.8V
• Voltage - I/o Low: 0.2V
• Current - Supply: 2.9mA
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Meter Type: Single Phase
• Output Voltage Range: 2.4 V to 2.6 V
• Output Current: 1 uA
• Input Voltage Range: 2.4 V to 2.6 V
• Input Current: 25 nA
• Power Dissipation: 500 mW
• Operating Temperature Range: - 40 C to + 85 C
• Mounting Style: SMD/SMT
• Ic Function: Single Phase Bi-directional Power / Energy IC
• Brief Features: On-Chip Functions, AC Or DC System Calibration, Power Supply Monitor
• Supply Voltage Range: 3.3V To 5V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: CDB5460AU - EVALUATION BOARD FOR CS5460A
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 598-1094-5

performed on each individual power meter, during
final calibration/test of the meter.
3.14 Protection Against High-voltage
In many power distribution systems, it is very likely
that the power lines will occasionally carry brief but
large transient spikes of voltage/current. Two com-
mon sources of such high-energy disturbances are
1) a surge in the line during a lightning storm, or 2)
a surge that is caused when a very inductive or ca-
pacitive load on the power line is suddenly turned
on (“inductive kick”). In these situations, the input
protection resistors and corresponding input filter
capacitors (discussed in the previous sections)
may not be sufficient to protect the CS5460A from
such high-frequency voltage/current surges. The
surges may still be strong enough to cause perma-
nent damage to the CS5460A. Because of this, the
designer should consider adding certain additional
components within the voltage/current channel in-
put circuitry, which can help to protect the
CS5460A from being permanently damaged by the
surges.
DS487F4
Input protection for single-ended input configurations, using resistive
and/or High-current Surges
N
Note that the digital interface is isolated using opto-isolators.
R2
To Service
120 Vrms
C2
R
L
C1
R1
divider and current shunt resistor.
L
470 nF
R
R3
R4
SHUNT
R5
L1
D1
500 Ω
L2
L3
L4
D3
Figure 20. Input Protection for Single-Ended Input Configurations
D2
100 µF
D4
0.1 µF
C3
5.1 Volt
C8
500 Ω
C5
C6
C4
C7
10
15
16
12
11
9
VIN+
VIN-
IIN+
IIN-
VREFOUT
VREFIN
0.1 µF
CS5460A
VA-
13
VA+
14
50
DGND
10 Ω
CPUCLK
PFMON
RESET
MODE
XOUT
SCLK
EOUT
4
VD+
SDO
EDIR
XIN
INT
SDI
CS
3
10 k Ω
50
17
8
2
1
24
19
7
23
6
5
20
22
21
0.1 µF
4.069 MHz
NC
NC
Referring to Figure 20, the addition of capacitors
C1 and C2 can help to further attenuate these
high-frequency power surges, which can greatly
decrease the chances that the CS5460A will be
damaged. Typical values for C1 and C2 may be on
the order of 10 pF, although the exact value is re-
lated to the reactive and resistive properties of the
voltage and current sensor devices. In addition, di-
odes D1 - D4 can help to quickly clamp a high volt-
age
voltage/current inputs, before such a surge can
damage the CS5460A. An example of a suitable
diode part number for this application is BAV199,
which has the ability to turn on very quickly (very
small turn-on time). A fuse could potentially serve
this purpose as well (not shown). R3 and R4 can
provide protection on the “-” sides of the two input
pairs. Set R3 = R1 and R4 = R5. Finally, placing
50 Ω resistors in series with the VA+ and VD+ pins
is another technique that has sometimes proven to
be effective in protecting the CS5460A from such
high-level, high-frequency voltage/current surges.
However, these 50 Ω resistors may not be neces-
sary if the protection on the analog input channels
is sufficient, and this is not the most attractive so-
5 k Ω
surge
20 k 20 k
+5 V
For Input Surge
Protection
voltage
10 k 10 k
+5 V
EMI susceptibility
presented
To reduce
1 k
1 k
1 k
1 k
1 k
1 k
CS5460A
across
47 k 47 k
+5 V
SCLK
SDO
CS
RST
GND
INT
SDI
the
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