STLM20 Ultra-low current 2.4 V precision analog temperature sensor Features ■ Precision analog voltage output temperature sensor ■ ±1.5 °C maximum temperature accuracy at 25 °C (±0.5 °C typical) ■ Ultra-low quiescent supply current: 4.8 µA (typ) and 8.0 µA (max) ■ Operating voltage range: 2.4 V to 5.
Contents STLM20 Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 Transfer function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4 DC and AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 5 Capacitive load . . . . . . . . . . . .
STLM20 List of tables List of tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8. Table 9. Table 10. Table 11. Table 12. Table 13. Table 14. Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 First order equations optimized for different temperature ranges . . . . . . . . . . . . . . . . . . . . . 6 Second order parabolic equation (VCC = 2.7 V) . . . . . . . . . . . . . . . . . . . . . . . . . .
List of figures STLM20 List of figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. 4/19 Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Connections (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Filter network for noisy environments or capacitive loads > 300 pF . . . . . . . . . . . . . . . . . . 10 VOUT vs.
STLM20 1 Description Description The STLM20 is a precision analog output temperature sensor for low current applications where maximizing battery life is important. It operates over a –55 °C to 130 °C (grade 7) or –40 °C to 85 °C (grade 9) temperature range. The power supply operating range is 2.4 V to 5.5 V. The maximum temperature accuracy of the STLM20 is ± 1.5 °C (±0.5 °C typ) at an ambient temperature of 25 °C and VCC of 2.7 V. The temperature error increases linearly and reaches a maximum of ±2.
Transfer function 2 STLM20 Transfer function The STLM20’s transfer function can be described in different ways, with varying levels of precision. A simple linear transfer function, with good accuracy near 25 °C is expressed as: Equation 1 (first order linear equation) V O = ( – 11.69mV ) ⁄ ° C × T + 1.8663 V Over the specified operating temperature range, the best accuracy can be obtained by using the parabolic transfer function: Equation 2 (second order parabolic equation) VO = (–3.
STLM20 Transfer function Table 3. Second order parabolic equation (VCC = 2.7 V) Parameter Conditions Min Typ Max TA = –55 °C 2.457 2.485 2.512 TA = –40 °C 2.292 2.318 2.343 TA = –30 °C 2.181 2.205 2.230 TA = –20 °C Temperature error based on: –6 2 –2 VOUT = (–3.88 x 10 × T ) + (–1.15 x 10 × T) + TA = 0 °C 1.8639 where T is the temperature TA = 25 °C 2.069 2.092 2.116 1.842 1.864 1.886 1.556 1.574 1.592 TA = 50 °C 1.255 1.279 1.303 TA = 85 °C 0.833 0.859 0.
Maximum ratings 3 STLM20 Maximum ratings Stressing the device above the rating listed in the absolute maximum ratings table may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above those indicated in the operating sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Table 5.
STLM20 4 DC and AC characteristics DC and AC characteristics This section summarizes the DC and AC characteristics of the device. The parameters in the DC and AC characteristics table that follows are derived from tests performed under the test conditions. Designers should check that the operating conditions in their circuit match the operating conditions when relying on the quoted parameters. Table 6.
Capacitive load 5 STLM20 Capacitive load The STLM20 will handle capacitive loads of up to 300 pF. Over the specified temperature range, the STLM20 has a maximum output impedance of 160 Ω. In a noisy environment, it may be advisable to add some filtering to minimize noise in the output voltage. A 0.1 µF capacitor added between the supply voltage and ground is recommended. In an extremely noisy environment, it may be necessary to add a low-pass filter network to the output of the device.
STLM20 Typical operating characteristics The graph shown in Figure 4 represents VOUT according to temperature. VOUT vs. temperature Figure 4. 2.50 VOUT (V) 6 Typical operating characteristics 2.00 1.50 1.00 0.50 0.00 –50 –20 10 40 70 100 130 Temperature (°C) Typical (VCC = 2.
Package mechanical data 7 STLM20 Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK® packages, depending on their level of environmental compliance. ECOPACK® specifications, grade definitions and product status are available at: www.st.com. ECOPACK® is an ST trademark.
STLM20 Package mechanical data Figure 5. SOT323-5L – 5-lead small outline transistor package outline 7091413_E 1. Drawing is not to scale. Table 8. SOT323-5L – 5-lead small outline transistor package mechanical data mm inches Symbol Typ Min Max Typ Min Max A – 0.80 1.10 – 0.031 0.043 A1 – 0 0.10 – 0.000 0.004 A2 0.90 0.80 1.00 0.035 0.031 0.039 b – 0.15 0.30 – 0.006 0.012 c – 0.10 0.22 – 0.004 0.009 D 2.00 1.80 2.20 0.079 0.071 0.087 E 2.10 1.80 2.
Package mechanical data Figure 6. STLM20 UDFN-4L – 4-lead (1.00 mm x 1.30 mm) package outline 7986858 Note: Drawing is not to scale. Table 9. UDFN-4L – 4-lead (1.00 mm x 1.30 mm) package mechanical data mm inches Symbol 14/19 Min Typ Max Min Typ Max A 0.45 0.50 0.55 0.018 0.020 0.022 A1 0 0.025 0.05 0 0.001 0.002 A3 0.119 0.127 0.177 0.0046 0.0050 0.0069 b 0.20 0.25 0.30 0.008 0.010 0.012 D 0.95 1.00 1.05 0.037 0.039 0.041 E 1.25 1.30 1.35 0.049 0.
STLM20 Package mechanical data Figure 7. Carrier tape for SOT323-5L and UDFN-4L packages P0 E P2 D T A0 F TOP COVER TAPE W B0 P1 CENTER LINES OF CAVITY K0 USER DIRECTION OF FEED AM03073v1 Table 10. Package Carrier tape dimensions for SOT323-5L and UDFN-4L packages W D E P0 P2 F A0 B0 K0 P1 T Unit Bulk Qty 8.00 SOT323-5L +0.30 –0.10 1.50 +0.10/ –0.00 4.00 2.00 3.50 1.75 ±0.10 ±0.10 ±0.10 ±0.05 2.25 ±0.10 2.40 ±0.10 1.22 ±0.10 4.00 0.30 mm 3000 ±0.10 ±0.05 8.00 +0.30 –0.
Package mechanical data Figure 8. STLM20 Reel schematic T 40mm min. Access hole At slot location B D C N A G measured Tape slot In core for Full radius Tape start 2.5mm min.width At hub AM04928v1 Table 11. Reel dimensions for 8 mm carrier tape - SOT323-5L and UDFN-4L packages A B (max) (min) 180 mm (7-inch) 1.5 mm Note: 16/19 C 13 mm ± 0.2 mm D N (min) (min) 20.2 mm 60 mm G 8.4 mm + 2/–0 mm T (max) 14.
STLM20 8 Part numbering Part numbering Table 12. Ordering information scheme Example: STLM20 DD 9 F Device type STLM20 Package W8 = SOT323-5L(1)(2) DD= UDFN-4L - ultra-thin DFN 4-lead(3) Temperature range 7 = –55 to 130°C 9 = –40 to 85°C Shipping method F = ECOPACK® package, tape & reel 1. Available in temperature grade 7 (–55 to 130 °C) only 2. SOT323-5L also referred to as SC70-5L 3. Available in temperature grade 9 (–40 to 85 °C) only Table 13.
Revision history 9 STLM20 Revision history Table 14. Document revision history Date Revision 28-Jun-2006 1 Initial release.
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