Data Sheet

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4. Electrical Characteristics
4.4. Reflow Profile
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Figure 4-1. ESP-WROOM-02 Reflow Profile
📖 Notes:
① Modem-sleep is used when such applications as PWM or I2S require the CPU to be working. In cases
where Wi-Fi connectivity is maintained and data transmission is not required, the Wi-Fi Modem circuit can
be shut down to save power, according to 802.11 standards (such as U-APSD). For example, in DTIM3,
when ESP8266EX sleeps for 300 ms and wakes up for 3 ms to receive Beacon packages from AP, the
overall average current consumption is about 15 mA.
② Light-sleep is used for applications whose CPU may be suspended, such as Wi-Fi switch. In cases
where Wi-Fi connectivity is maintained and data transmission is not required, Wi-Fi Modem circuit and
CPU can be shut down to save power, according to 802.11 standards (such as U-APSD). For example, in
DTIM3, when ESP8266EX sleeps for 300 ms and wakes up for 3 ms to receive Beacon packages from
AP, the overall average current consumption is about 0.9 mA.
③ Deep-sleep is for applications that do not require Wi-Fi connectivity and only transmit data over long time
lags, e.g., a temperature sensor that measures temperature every 100s. For example, when ESP8266EX
sleeps for 300s then wakes up to connect to AP (taking about 0.3 ~ 1s), the overall average current
consumption is far less than 1 mA. The current consumption of 20 μA was obtained at the voltage of 2.5V.
Temperature (℃)
Soldering time
> 30s
Ramp-up zone
Time (sec.)
50
150
0
25
1 ~ 3℃/s
0
200
250
200
Peak Temp.
235 ~ 250℃
3 ~ 5℃/s
Cooling down zone
Preheating zone
150 ~ 200℃ 60 ~ 120s
100
217
50
100 250
Ramp-up zone — Temp.: <150℃ Time: 60 ~ 90s Ramp-up rate: 1 ~ 3℃/s
Preheating zone — Temp.: 150 ~ 200℃ Time: 60 ~ 120s Ramp-up rate: 0.3 ~ 0.8℃/s
Reflow soldering zone — Peak Temp.: 235 ~ 250℃ (<245℃ recommended) Time: 30 ~ 70s
Cooling down zone — Temp.: 217 ~ 170℃ Ramp-down rate: 3 ~ 5℃/s
Solder — Sn&Ag&Cu Lead-free solder (SAC305)
Espressif
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2017.10