HC55185_06 Datasheet, PDF (7/20 Pages) Intersil Corporation – VoIP Ringing SLIC Family

HC55185
Electrical Specifications
Unless Otherwise Specified, T_A = -40°C to +85°C for industrial (I) grade and T_A = 0°C to +85°C for commercial
(C) grade, V_BL = -24V, V_BH = -100V, -85V or -75V, V_CC = +5V, AGND = BGND = 0V, loop current limit = 25mA.
All AC parameters are specified at 600Ω 2-wire terminating impedance over the frequency band of 300Hz to
3.4kHz. Protection resistors = 0Ω. (Continued)
PARAMETER
TEST CONDITIONS
MIN TYP MAX UNITS
V_BH to 4-Wire
300Hz ≤ f ≤ 1kHz
1kHz < f ≤ 3.4kHz
-
40
-
dB
-
45
-
dB
NOTES:
3. These parameters are controlled via design or process parameters and are not directly tested. These parameters are characterized upon initial
design release and upon design changes which would affect these characteristics.
4. Differential Ringing Gain is measured with VRS = 0.795V_RMS for -100V devices, VRS = 0.663 V_RMS for -85V devices and VRS = 0.575V_RMS
for -75V devices.
5. Longitudinal Balance is tested per IEEE455-1985, with 368Ω per Tip and Ring terminal.
6. These parameters are tested 100% at room temperature. These parameters are guaranteed not tested across temperature via statistical
characterization and design.
7. The power dissipation is based on actual device measurements and will be less than worst case calculations based on data sheet supply current
limits.
8. Characterized with 2 x 10μs, and 10 x 1000μs first level lightning surge waveforms (GR-1089-CORE)
9. For Unbalanced Ringing the Tip terminal is offset to 0V and the Ring terminal is centered at Vbh/2 + 0.5V.
Special Considerations for the QFN
Package
The new QFN package offers a significant footprint reduction
(65%) and improved thermal performance with respect to the
28 lead PLCC. To realize the thermal enhancements and
maintain the high voltage (-100V) performance, the exposed
leadframe should be soldered to a power/heat sink plane
that is electrically connected to the high battery supply (V_BH)
within the application board. This approach distributes the
heat evenly across the board and is accomplished by using
conductive thermal vias. Reference technical brief TB379
and AN9922 for additional information on thermal
characterization and board layout considerations.
Product Family Cross Reference
The following table provides an ordering and functional cross
reference for the existing HC55180 through HC55184
products and the new and improved HC55185 product.
TABLE 1. PRODUCT CROSS REFERENCE
EXISTING DEVICES
FUNCTIONAL EQUIVALENT
HC55180CIM, HC55180DIM
None Offered
HC55181AIM, HC55182AIM
HC55185AIM
HC55181BIM, HC55182BIM
HC55185BIM
HC55181CIM, HC55182CIM
HC55185CIM
HC55181DIM, HC55182DIM
HC55185DIM
HC55183ECM, HC55184ECM
HC55185ECM
Any of the HC55185 products may be used without the
battery switch function by shorting the supply pins VBL and
VBH together. This provides compatibility with HC55180
type applications which do not require the battery switch.
Application Circuit Modifications
The HC55185 basic application circuit is nearly identical to
that of the HC55180 through HC55184. The HC55185
requires an additional resistor to program the transient
current limit feature. This programming resistor is connected
from pin 16 (TL) to ground. In addition some component
values have been changed to improve overall device
performance. The table below lists the component value
changes required for the HC55185 application circuit.
TABLE 2. COMPONENT VALUE CHANGES
REFERENCE
HC55180 - 184
HC55185
RS
210kΩ
66.5kΩ
RP1
RP2
CFB
≥ 35Ω
≥ 35Ω
0.47μ
≥ 49Ω
≥ 49Ω
4.7μ
The value of RS is based on a 600Ω termination impedance
and RP1 = RP2 = 49.9Ω. Design equations are provided to
calculate RS for other combinations of termination and
protection resistance.
The CFB capacitor must be non-polarized for proper device
operation in Reverse Active. Ceramic surface mount
capacitors (1206 body style) are available from Panasonic
with a 6.3V voltage rating. These can be used for CFB since
it is internally limited to approximately ±3V. The CDC
capacitor may be either polarized or non polarized.
Parametric Improvements
The most significant parametric improvement of the
HC55185 is reduction in Idle Channel Noise. This
improvement was accomplished by redistributing gains in
the impedance matching loop. The impact to the application
circuit is the change in the impedance programming resistor
RS. The redistribution of gains also improves AC
performance at the upper end of the voice band.
7
FN4831.14
December 18, 2006